browser-close 相关问题

create = open("lol.balbes.txt", 'w') oldfile = open("mbox-short.txt") 对于旧文件中的行：线=线.上线 = str(线) 创建.write(行) 创建.close() 我

连接=engine.raw_connection() 光标 = 连接.cursor() cursor.callproc('transfer', [1, 2, 1000])# 获取结果参数结果 = 列表(cursor.fetchall()) 光标.close() 连接.com...

编写器出现不支持的函数截断错误：close()

RA = pd.read_excel（文件路径，标题= 0，sheet_name =“数据”） ivot_df = pd.DataFrame(RA) #插入枢轴枢轴=枢纽_df [过滤器2] .枢轴_表（指数= ['a'，'b'，'c']，值= ['总计1'，'总计...

下面的Browser Engine图和JS Runtime图之间的桥梁是什么？

我一直在阅读有关浏览器如何工作以及浏览器的组件是什么的内容。我看到了各种关于浏览器如何解析 JS 和渲染过程等的文章，但我不是

子控件中的绑定命令？

我有一个 UserControl，用作窗口对话框的“模板”。它包含一个关闭按钮和一个取消按钮。我有一个 UserControl，用作窗口对话框的“模板”。它包含一个关闭按钮和一个取消按钮。 <UserControl x:Class="TombLib.WPF.Controls.WindowControlButtons" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:local="clr-namespace:TombLib.WPF.Controls" mc:Ignorable="d" xmlns:darkUI="clr-namespace:DarkUI.WPF;assembly=DarkUI.WPF" xmlns:vm="clr-namespace:TombLib.WPF.ViewModels" xmlns:sg="clr-namespace:SpacedGridControl;assembly=SpacedGridControl" d:DesignHeight="100" d:DesignWidth="300" x:Name="root"> <StackPanel VerticalAlignment="Center" HorizontalAlignment="Right" Height="Auto" Orientation="Horizontal"> <Button Name="oKButton" Margin="{x:Static darkUI:Defaults.MediumThickness}" Width="100" Height="Auto" Command="{Binding Close}" CommandParameter="{Binding Window}" Content="OK"></Button> <Button Name="cancelButton" Margin="{x:Static darkUI:Defaults.MediumThickness}" Width="100" Height="Auto" Command="{Binding Path=Cancel}" CommandParameter="{Binding Window}" Content="Cancel"></Button> </StackPanel> </UserControl> public partial class WindowControlButtons : UserControl { public static readonly DependencyProperty CancelProperty = DependencyProperty.Register( nameof(Cancel), typeof(ICommand), typeof(WindowControlButtons), new PropertyMetadata(null)); public ICommand Cancel { get { return (ICommand)GetValue(CancelProperty); } set { SetValue(CancelProperty, value); } } public static readonly DependencyProperty CloseProperty = DependencyProperty.Register( nameof(Close), typeof(ICommand), typeof(WindowControlButtons), new PropertyMetadata(null)); public ICommand Close { get { return (ICommand)GetValue(CloseProperty); } set { SetValue(CloseProperty, value); } } public static readonly DependencyProperty WindowParameter = DependencyProperty.Register( nameof(Window), typeof(object), typeof(WindowControlButtons), new PropertyMetadata(null)); public object? Window { get { return GetValue(WindowParameter); } set { SetValue(WindowParameter, value); } } public WindowControlButtons() { InitializeComponent(); } } 我想在以下窗口中使用它： <Window x:Class="TombLib.WPF.Windows.SelectIdWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:TombLib.WPF.Windows" mc:Ignorable="d" xmlns:ctrl="clr-namespace:TombLib.WPF.Controls" xmlns:vm="clr-namespace:TombLib.WPF.ViewModels" xmlns:sg="clr-namespace:SpacedGridControl;assembly=SpacedGridControl" xmlns:darkUI="clr-namespace:DarkUI.WPF;assembly=DarkUI.WPF" Title="SelectIdWindow" Height="100" Width="300" d:DataContext="{d:DesignInstance Type=vm:SelectIdViewModel }" x:Name="Self"> <sg:SpacedGrid Margin="{x:Static darkUI:Defaults.MediumThickness}">  <ctrl:WindowControlButtons DataContext="{Binding ElementName=Self}" Window="{Binding ElementName=Self, Mode=OneWay}" Close="{Binding CloseCommand,Mode=OneWay}" Cancel="{Binding CancelCommand,Mode=OneWay}" Height="Auto" Width="Auto" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" HorizontalAlignment="Right"/> </sg:SpacedGrid> </Window> public partial class SelectIdWindow : Window { public ICommand? CloseCommand { get; set; } public ICommand? CancelCommand { get; set; } public SelectIdWindow() { CloseCommand = new WindowCloseCommand(); InitializeComponent(); } } public class SelectIdViewModel { public string RequestedId { get; set; } = string.Empty; public IEnumerable<string> TakenIds { get; set;} public SelectIdViewModel(IEnumerable<string> takenIDs) { TakenIds = takenIDs; } } 但是，当我打开窗口时如下： SelectIdWindow w = new SelectIdWindow(); var takenIDs = Entities.Select(kv => kv.Key.Name); w.DataContext = new SelectIdViewModel(takenIDs); w.ShowDialog(); 我在绑定 WindowControlButtons 时收到以下错误： DataContext 显式设置为 Self，它应该代表 Window，而不是 ViewModel。我在这里做错了什么？绑定错误表明问题出在 Button.ICommand 属性上：要修复此问题，请在 WindowControlButtons 绑定中添加 ElementName=root，以便绑定到声明的依赖项属性而不是 DataContext： <UserControl x:Class="TombLib.WPF.Controls.WindowControlButtons" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:local="clr-namespace:TombLib.WPF.Controls" mc:Ignorable="d" xmlns:darkUI="clr-namespace:DarkUI.WPF;assembly=DarkUI.WPF" xmlns:vm="clr-namespace:TombLib.WPF.ViewModels" xmlns:sg="clr-namespace:SpacedGridControl;assembly=SpacedGridControl" d:DesignHeight="100" d:DesignWidth="300" x:Name="root"> <StackPanel VerticalAlignment="Center" HorizontalAlignment="Right" Height="Auto" Orientation="Horizontal"> <Button Name="oKButton" ... Command="{Binding Close, ElementName=root}" CommandParameter="{Binding Window, ElementName=root}" Content="OK"/> <Button Name="cancelButton" ... Command="{Binding Path=Cancel, ElementName=root}" CommandParameter="{Binding Window, ElementName=root}" Content="Cancel"/> </StackPanel> </UserControl>

如何在 Vuetify.js 中单击附加图标时调用函数？

我需要append-icon="close"来调用@click="clearSearch()" 现在我正在使用一个专用按钮来实现它：我需要 append-icon="close" 打电话给 @click="clearSearch()" 现在我正在使用专用按钮来实现它： <v-text-field v-model="search" class="search" label="search" prepend-icon="search" append-icon="close"> </v-text-field> <v-btn @click="clearSearch()"></v-btn> 我尝试添加append-icon-cb="clearSearch()"但它不起作用，我不知道为什么我也尝试过简单地使用clearable，它会清除输入，但所有元素都保持“过滤”状态。我不知道 clearable 是如何工作的，但我的 clearSearch() 方法只是这样做： clearSearch() {this.search = ""} 并且它有效，这就是为什么我使用自定义 clear input 方法使用 @click:append="clearSearch"，:append-icon-cb 已弃用。（来源）解决了，解决方法如下：为了避免这个问题，您应该使用 : 符号绑定属性： :append-icon-cb="clearSearch" 并且不要放()，否则它将无法工作（正如@Traxo提到的）我认为如果你删除 () 应该可以工作，因为包含 () 后，你立即只需调用一次函数即可。编辑：不要忘记冒号: 所以： :append-icon-cb="clearSearch" 但这发生了变化：对于附加图标，例如 append-icon="mdi-magnify-plus-outline", 你就这样做 @click:append="zoomIn"。但是对于附加外部图标，例如 append-outer-icon="mdi-plus-circle-outline"，` 您必须添加单词“append”，即 @click:append-outer="addMore" 因此，这将适用于 Vue2 <v-text-field solo append-outer-icon="mdi-plus-circle-outline" @click:append-outer="addMore" > </v-text-field> 只需将 :append-icon-cb="() => (e1 = !e1)" 更改为 @click:append="() => (e1 = !e1)" 即可完美运行并删除警告...

脚本无法在我的引导模式中工作

希望这不是一个愚蠢的问题，但我已经没有主意了...... 所以我有这个模式： 1.scala.html 希望这不是一个愚蠢的问题，但我已经没有主意了...... 所以我有这个模式： 1.scala.html <div class="feat" id="cor" data-toggle="tooltip" data-placement="bottom" title="add conference role"><div data-toggle="modal" data-target="#conf-role-menu-modal">Conference Role</div></div> <div class="modal fade" id="conf-role-menu-modal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true"> <div class="modal-dialog"> <div class="modal-content"> <div class="modal-header"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> <h4 class="modal-title" id="myModalLabel">Modal title</h4> </div> <div class="modal-body-conf-role-menu"> <script type="text/javascript"> $(function(){ $(".modal-body-conf-role-menu").load("@routes.Application.areaConferenceRole(id,idenv)"); }); </script> </div> <div class="modal-footer"> <button type="button" class="btn btn-default" data-dismiss="modal">Close</button> </div> </div> </div> </div> 使用模态主体中的脚本，我尝试加载此页面： 2.scala.html @(id:String, idenv:String) @Main("Add area") { <form action="@routes.Application.areaPostConferenceRole(id,idenv)" method="POST"> First Name: <input type="text" name="first_name" id="first" class="form-control"> Last Name : <input name="last_name" class="form-control"> <script type="text/javascript"> $( document ).ready(function() { // Handler for .ready() called. $( "#first" ).focus(function() { alert( "Handler for .focus() called." ); }); }); </script> </form> } 页面加载正常。我在我的模态中看到它...... 问题是我的页面 2.scala.html 中的脚本无法运行。我不明白为什么......如果我从我尝试在模态中加载的页面之外尝试它们，它们就会起作用...... $( document ).ready(function(){}); 永远不会在模态中到达，因为加载页面时已经触发了此事件（模态在之后加载...）尝试直接插入脚本，如下所示： <script type="text/javascript"> $( "#first" ).focus(function() { alert( "Handler for .focus() called." ); }); </script> 当引导模式弹出时，shown.bs.modal事件将被触发。这是例子。 $('#myModal').on('shown.bs.modal', function () { $('#myInput').trigger('focus') }) Full documentation. https://getbootstrap.com/docs/4.0/components/modal/ 试试这个我已经准备好这个功能了 $('#myModal').on('shown.bs.modal', function () { // Your script here }); $(document).on('shown.bs.modal', '#myModal', function () { // Your script here });

MathML (firefox) 中不显示括号

MathML代码是这样的：分钟 MathML代码是这样的： <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>min</mi><mfenced open="(" close=")"><mrow><mn>9</mn><mo>,</mo><mn>6</mn></mrow></mfenced><mo>=</mo></mrow></math> 遗憾的是，它显示时没有括号。（参见https://prnt.sc/FBuGkh1NtM-7）我在这里做错了什么？谢谢！ <math display="block"> <mrow> <mo fence="true" form="prefix">(</mo> <mn>9</mn> <mo fence="true" form="postfix">)</mo> </mrow> </math> 这有效。但不知道为什么之前的 MathML 不起作用。 “mfenced”似乎已被贬值并被“mo”取代。 “mrow”可用于组子表达式并为方程提供层次结构： <mrow> <mi>f</mi> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow>

Django-channels 实例关闭时间过长而被杀死

谁能告诉我可能是什么问题？警告应用程序实例谁能告诉我可能是什么问题？警告应用程序实例 wait_for=> 连接关闭时间过长并被终止。我的阿斯吉 "^subscription", channels_jwt_middleware(MyConsumer.as_asgi(schema=schema)) ) application = ProtocolTypeRouter({ "http": django_asgi_app, "websocket": QueryAuthMiddleware( URLRouter([ subscription_url, ]) ), })``` my custom MyConsumer ```class MyConsumer(GraphQLWSConsumer): def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.profile_id = None async def __call__(self, scope, receive, send): user = scope.get("user", None) time_zone = await get_current_timezone(user) self.profile_id = scope.get("active_profile_id", None) self.timezone = time_zone if time_zone else settings.TIME_ZONE await super().__call__(scope, receive, send) async def connect(self): await super().connect() await change_status(True, self.profile_id) async def disconnect(self, close_code, *args, **kwargs): await super().disconnect(close_code) await change_status(False, self.profile_id)``` 解决我的问题 daphne -b 0.0.0.0 -p $SERVER_PORT --application-close-timeout 60 --proxy-headers server.asgi:application

NG8001：“app-welcome”不是已知元素：

我的 Angular 应用程序遇到问题，收到错误 8001。我不知道如何处理它。谁能帮我这个？谢谢你！应用程序组件.html {{标题}}&l... 我的 Angular 应用程序遇到问题，收到错误 8001。我不知道如何处理它。谁能帮我这个？谢谢！ app.component.html <h1>{{ title }}</h1> <p>Congratulations! Your app is running. 🎉</p> <app-welcome></app-welcome> app.component.ts import { Component } from '@angular/core'; import { CommonModule } from '@angular/common'; import { RouterOutlet } from '@angular/router'; @Component({ selector: 'app-root', standalone: true, imports: [CommonModule, RouterOutlet], templateUrl: './app.component.html', styleUrl: './app.component.css' }) export class AppComponent { title = 'XYZCARS'; } welcome.component.ts import { Component } from '@angular/core'; @Component({ selector: 'app-welcome', templateUrl: './welcome.component.html', styleUrl: './welcome.component.css' }) export class WelcomeComponent { car = 'toyota'; } 我的项目最初没有 app.module.ts 文件。我自己添加了它并根据网上找到的一些信息进行了配置，但问题仍然存在并且仍未解决。谁能帮我解决这个问题吗？ app.module.ts import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { WelcomeComponent } from './welcome/welcome.component'; import { AppComponent } from './app.component'; @NgModule({ declarations: [ AppComponent, WelcomeComponent ], imports: [ BrowserModule ], providers: [], bootstrap: [AppComponent] }) export class AppModule { } 如果您正在 Angular 17 中创建项目->使用这些命令 ng app --no-standalone 然后你就得到了 app.module.ts 文件。

如果类型是从变量进行数据绑定，则通过 <object> 标签在 Angular 中显示 pdf 无法在 Chrome 中工作

我正在尝试通过标签在 Chrome 中显示 pdf。如果我手动编写类型，它会起作用：不工作但是... 我正在尝试通过 <object> 标签在 Chrome 中显示 pdf。如果我手动写 type: 就可以了 <object [data]="getUrl(true)" type="application/pdf"> Not working </object> 但如果我从变量读取类型则不会： <object [data]="getUrl(true)" [type]="file.mimeType"> Not working </object> 为什么？这是一些非常奇怪的错误，还是我做错了什么可怕的事情。这里是plunkr。它可以在 Firefox 中运行（所有 4 个对象都会显示），但不能在 Chrome 中运行 (Version 74.0.3729.169 (Official Build) (64-bit))：我遇到了同样的问题，但我不明白原因。就我而言，我决定在基于 Blink 引擎的浏览器中使用“embed”元素而不是“object”元素。 <ng-template #blinkPlatformViewer> <embed [src]="getUrl(true)" [type]="file.mimeType"/> </ng-template> <object *ngIf="!isBlinkPlatform; else blinkPlatformViewer" [data]="getUrl(true)" [type]="file.mimeType"> Not working </object> import { Platform } from '@angular/cdk/platform'; import { DomSanitizer, SafeResourceUrl } from '@angular/platform-browser'; export class FileContentComponent { constructor(private readonly sanitizer: DomSanitizer, private readonly platform: Platform) { } get isBlinkPlatform(): boolean { return this.platform.BLINK; } }

ESLint：解析错误：意外的标记：

大家好我正在将我的 vue3 项目从 js 迁移到 typescript，我遇到了这个问题：这是我在 .vue 文件中的代码 const toto = (msg: string) => { </desc> <question vote="7"> <p>大家好，我正在将我的 vue3 项目从 js 迁移到 typescript，我遇到了这个问题：</p> <p><a href="https://i.stack.imgur.com/y5tG8.png" target="_blank"><img src="https://cdn.txt58.com/i/AWkuc3RhY2suaW1ndXIuY29tL3k1dEc4LnBuZw==" alt=""/></a></p> <p>这是我在 .vue 文件中的代码</p> <pre><code><script setup lang="ts"> const toto = (msg: string) => { console.log(msg) } </script> </code></pre> <p>这是我的 eslintrc.js</p> <pre><code>module.exports = { 'env': { 'browser': true, 'es2021': true }, 'extends': [ 'eslint:recommended', 'plugin:vue/vue3-essential' ], 'parserOptions': { 'ecmaVersion': 13, 'sourceType': 'module' }, 'plugins': [ 'vue' ], 'rules': { 'vue/multi-word-component-names': 'off', 'vue/object-curly-spacing': [2, 'always'], 'vue/html-closing-bracket-spacing': [2, { 'selfClosingTag': 'always' }], 'vue/max-attributes-per-line': [2, { 'singleline': { 'max': 1 }, 'multiline': { 'max': 1 } }], 'semi': [2, 'never'] } } </code></pre> </question> <answer tick="true" vote="10"> <p>您需要配置 eslint 以支持 typescript，因为 eslint 不支持开箱即用。首先，您需要安装<a href="https://www.npmjs.com/package/@typescript-eslint/parser" rel="nofollow noreferrer">@typescript-eslint/parser</a>，然后安装<a href="https://www.npmjs.com/package/@typescript-eslint/eslint-plugin" rel="nofollow noreferrer">@typescript-eslint/eslint-plugin</a>。安装完这些后，请按如下方式更新您的配置 - </p> <pre><code>module.exports = { 'env': { 'browser': true, 'es2021': true, node: true }, 'extends': [ 'eslint:recommended', 'plugin:vue/vue3-essential' ], 'parserOptions': { 'ecmaVersion': 12, 'sourceType': 'module', parser: '@typescript-eslint/parser' }, 'plugins': [ 'vue', '@typescript-eslint' ], 'rules': { 'vue/multi-word-component-names': 'off', 'vue/object-curly-spacing': [2, 'always'], 'vue/html-closing-bracket-spacing': [2, { 'selfClosingTag': 'always' }], 'vue/max-attributes-per-line': [2, { 'singleline': { 'max': 1 }, 'multiline': { 'max': 1 } }], 'semi': [2, 'never'] } } </code></pre> </answer> <answer tick="false" vote="1"> <p>就我而言，问题是我使用解析器选项作为数组，而不是字符串：</p> <pre><code> parserOptions: { - parser: ['@typescript-eslint/parser'], + parser: '@typescript-eslint/parser', }, </code></pre> </answer> <answer tick="false" vote="0"> <p>如果你在项目中同时使用 JS 和 TS，此配置有帮助</p> <pre><code> overrides: [ { files: ['*.vue'], parser: 'svelte-eslint-parser', parserOptions: { parser: { // Specify a parser for each lang. ts: '@typescript-eslint/parser', js: 'espree', typescript: '@typescript-eslint/parser' } } } ], </code></pre> </answer> <answer tick="false" vote="-1"> <p>我在节点 v12.22.9 上遇到了这个问题。通过升级到 v14.21.2，我不再遇到解析错误。您可以使用命令升级/安装</p> <pre><code>nvm install v14.21.2 </code></pre> </answer> </body></html>

选中/取消选中 mat-checkbox 未正确返回 true 或 false

我正在使用 Angular 15 和 Angular Material 14，下面是我用来显示复选框列表的 HTML 代码我正在 Angular 15 和 Angular Material 14 工作，下面是我用来显示复选框列表的 HTML 代码 <div *ngFor="let control of checkboxArray.controls;let i = index" > <mat-checkbox [formControl]="control" (input)="validateInputs(notificationForm)" [checked]="control.value" (change)="control.checked=$event.checked;onCheckedChange(i);"> {{ checkboxItems[i].name }} </mat-checkbox> </div> 下面是Angular中onCheckedChange函数的代码 onCheckedChange(index: number) { this.sortCheckboxArray(); const checkboxItem = this.checkboxItems[index]; const control = this.checkboxArray.at(index); if (control) { if (control.value) { this.lists.push(checkboxItem.id.toString()); } else { this.lists.pop(checkboxItem.id.toString()); } } this.updateSubscriberGroupsCount(); this.cdr.detectChanges(); } 当我选中复选框时，在这个 onCheckedChange 函数中，control.value 始终返回 false。哪里出了问题？无法理解.. 这是一个工作版本，复选框逻辑工作正常，希望有帮助！我们需要使用control.value获取表单组，但我们还需要访问内部表单控件，然后获取复选框值！ import { CommonModule } from '@angular/common'; import { Component } from '@angular/core'; import { FormArray, FormControl, FormGroup, ReactiveFormsModule, } from '@angular/forms'; import { bootstrapApplication } from '@angular/platform-browser'; import 'zone.js'; import { MatCheckboxModule } from '@angular/material/checkbox'; @Component({ selector: 'app-root', standalone: true, imports: [CommonModule, ReactiveFormsModule, MatCheckboxModule], template: ` <form [formGroup]="form"> <div formArrayName="array"> <div *ngFor="let control of checkboxArray.controls;let i = index" [formGroupName]="i"> <mat-checkbox formControlName="test" style="margin-bottom: 15px;" (change)="onCheckedChange(i);"> {{ checkboxItems[i].name }} </mat-checkbox> </div> </div> </form> `, }) export class App { name = 'Angular'; form = new FormGroup({ array: new FormArray([]), }); lists = []; checkboxItems: any = []; ngOnInit() { this.add(); this.add(); this.add(); } add() { this.checkboxArray.push( new FormGroup({ test: new FormControl(false), }) ); this.checkboxItems.push({ name: 'test' }); } get checkboxArray() { return this.form.get('array') as FormArray; } onCheckedChange(index: number) { // this.sortCheckboxArray(); // const checkboxItem = this.checkboxItems[index]; const control = this.checkboxArray.at(index); if (control) { if (control.value.test) { console.log('checked'); // this.lists.push(checkboxItem.id.toString()); } else { console.log('not checked'); // this.lists.pop(checkboxItem.id.toString()); } } // this.updateSubscriberGroupsCount(); // this.cdr.detectChanges(); } } bootstrapApplication(App); 堆栈闪电战

使用python的mechanize自动网站登录

我正在尝试自动登录一个网站，该网站的登录表单具有以下 HTML 代码（摘录）：我正在尝试自动登录一个网站，其登录表单具有以下 HTML 代码（摘录）： <tr> <td width="60%"> <input type="text" name="username" class="required black_text" maxlength="50" value="" /> </td> <td> <input type="password" name="password" id="password" class="required black_text" maxlength="50" value="" /> </td> <td colspan="2" align="center"> <input type="image" src="gifs/login.jpg" name="Login2" value="Login" alt="Login" title="Login"/> </td> </tr> 我正在使用python的mechanize模块进行网页浏览。以下是代码： br.select_form(predicate=self.__form_with_fields("username", "password")) br['username'] = self.config['COMMON.USER'] br['password'] = self.config['COMMON.PASSWORD'] try: request = br.click(name='Login2', type='image') response = mechanize.urlopen(request) print response.read() except IOError, err: logger = logging.getLogger(__name__) logger.error(str(err)) logger.debug(response.info()) print str(err) sys.exit(1) def __form_with_fields(self, *fields): """ Generator of form predicate functions. """ def __pred(form): for field_name in fields: try: form.find_control(field_name) except ControlNotFoundError, err: logger = logging.getLogger(__name__) logger.error(str(err)) return False return True return __pred 不知道我做错了什么...... 谢谢该网站有可能在登录期间使用java脚本进行回发。我记得很清楚，对于 ASP .Net 站点，您需要获取隐藏表单字段，例如 VIEWSTATE 和 EVENTTARGET 并将它们发布到新 Page 。您为什么不发送问题网站的链接？之后就变得相对容易弄清楚了尝试使用 Selenium 和 PhantomJS from selenium import PhantomJS import platform if platform.system() == 'Windows': # .exe for Windows PhantomJS_path = './phantomjs.exe' else: PhantomJS_path = './phantomjs' service_args = [ # Proxy (optional) '--proxy=<>', '--proxy-type=http', '--ignore-ssl-errors=true', '--web-security=false' ] browser = PhantomJS(PhantomJS_path, service_args=service_args) browser.set_window_size(1280, 720) # Window size for screenshot (optional) login_url = "<url_here>" # Credentials Username = "<insert>" Password = "<insert>" # Login browser.get(login_url) browser.save_screenshot('login.png') print browser.current_url browser.find_element_by_id("<username field id>").send_keys(Username) browser.find_element_by_id("<password field id>").send_keys(Password) browser.find_element_by_id("<login button id>").click() print (browser.current_url) browser.get(scrape_url) print browser.page_source browser.quit() ''' python 和 pycharm 设置路径变量点维辛检查包管理器 python 如何安装新版本 python最新版本 - python 3.7.2 用户环境变量蟒蛇 pyton 中的命令行 '''

带有使用 requireJS 的 javascript 模块的 Flutter Web 项目（Flutter Web 中的 Monaco 编辑器）

我正在尝试在 Flutter Web 中使用 Monaco 编辑器。我看到的最简单的方法是同步加载所有资源示例。这是一个独立的 html 文件：我正在尝试在 Flutter Web 中使用 Monaco 编辑器。我看到的最简单的方法是同步加载所有资源示例。这是一个独立的 html 文件： <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <link rel="stylesheet" data-name="vs/editor/editor.main" href="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs/editor/editor.main.css" /> <style> @font-face { font-family: "codicon", src: url("https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs/base/browser/ui/codicons/codicon.ttf") format("truetype") } </style> <title>Monaco</title> </head> <body> <h2>Monaco Editor Sync Loading Sample</h2> <div id="code" style="width: 800px; height: 600px; border: 1px solid grey"></div> <script> var require = { paths: { vs: "https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs" } }; </script> <script src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs/loader.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs/editor/editor.main.nls.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs/editor/editor.main.js"></script> <script> var editor = monaco.editor.create(document.getElementById("code"), { value: ['function x() {', '\tconsole.log("Hello world!");', '}'].join('\n'), language: "javascript", additionalCssClassName: "code" }); </script> </body> </html> 我的问题是：如何修改示例 Flutter Web 项目的 index.html 文件，以便加载所有必需的资源？线路好像有问题 var require = { paths: { vs: "https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.44.0/min/vs" } }; 因为 flutter 构建永远不会完成（卡在某个地方。）我看到 Flutter 本身使用 requirejs，并且可能存在我不知道如何解决的冲突。如果您知道如何执行此操作，请发布一个 Fluter Web index.html 文件，该文件加载编辑器所需的所有 js 文件。谢谢你， T https://github.com/Hua777/flutter_monaco_editor 我已经大致完成了flutter版的monaco编辑器。但还不完美，希望对你有帮助。

为什么我在GWT中无法隐藏UiBinder中的DialogBox？

在 Test.ui.xml 中测试一些小部件.. 在Test.ui.xml <g:DialogBox ui:field="wishlistDialogBox" autoHide="true"> <g:caption>Test</g:caption> <g:HTMLPanel> some widgets..</g:HTMLPanel> </g:DialogBox> 运行后，应用程序仍然显示DialogBox，所以我尝试在TestView.java中为“wishlistDialogBox”设置隐藏，但没有成功。 @UiField DialogBox wishlistDialogBox; @Inject public TestView(final Binder binder) { widget = binder.createAndBindUi(this); wishlistDialogBox.hide(); } 然后我在TestPresenter.java中为它设置了隐藏，但仍然不起作用 @Override protected void onBind() { super.onBind(); getView().getWishlistDialogBox().hide(); } 怎么了，古德尔根本没有解释。另外，DialogBox如何重复使用？当谈论将它们添加到 DOM 时，DialogBox（以及一般的 PopupPanel）不像任何其他小部件那样工作。您永远不应该像以前那样将它们直接附加到它（即 panel.add(yourDialogBox) 或在 UiBinder XML 文件中）。相反，您应该创建它们，然后简单地调用 hide()/show() 以及类似的方法，以使其显示/隐藏（即，在 DOM 的末尾附加/分离）。对我有用的是与任何其他小部件分开创建一个对话框。所以它有自己的 Java 文件和自己的 ui.xml 文件： UiBinder xml文件： <ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder" xmlns:g="urn:import:com.google.gwt.user.client.ui"> <g:DialogBox ui:field="dialog"> <g:caption>My Dialog</g:caption> <g:HTMLPanel> <g:Button ui:field="closeButton" text="close" /> </g:HTMLPanel> </g:DialogBox> </ui:UiBinder> Java 文件： public class MyDialog { // here you do not inherit anything private static MyDialogUiBinder uiBinder = GWT.create(MyDialogUiBinder.class); interface MyDialogUiBinder extends UiBinder<Widget, MyDialog> { } @UiField DialogBox dialog; @UiField Button closeButton; public MyDialog() { // make cast to DialogBox dialog = (DialogBox) (uiBinder.createAndBindUi(this)); } public void hide() { dialog.hide(); } public void show() { dialog.center(); } @UiHandler("closeButton") public void onClick(ClickEvent event) { hide(); } } 最后我想出了一个办法，那就是把DialogBox放到一个看不见的HTMLPanel <g:HTMLPanel visible="false"> <g:DialogBox ui:field="wishlistDialogBox" autoHide="true"> <g:caption>Test</g:caption> <g:HTMLPanel> some widgets..</g:HTMLPanel> </g:DialogBox> </g:HTMLPanel> 然后像往常一样调用 show & hide DialogBox，即使 DialogBox 被包裹在一个看不见的 DialogBox 中，它也会显示 HTMLPanel。 getView().getWishlistDialogBox().show();

防止打开的窗口覆盖 opener 的 `close` 方法

我有一个 test1.html 文件，仅包含以下代码： janela = window.open("http://localhost/test2.html","_blank","width=1000,height=400,left=600,top=0"); </...</desc> <question vote="1"> <p>我有一个 <pre><code>test1.html</code></pre> 文件，其中仅包含以下代码：</p> <pre><code><script> janela = window.open("http://localhost/test2.html","_blank","width=1000,height=400,left=600,top=0"); </script> </code></pre> <p>上面的代码将打开窗口<pre><code>test2.html</code></pre>，其中包含以下代码：</p> <pre><code><script> opener.window.janela.close = null; </script> </code></pre> <p>现在，在窗口 <pre><code>test1.html</code></pre> 上，如果我尝试关闭刚刚使用 <pre><code>janela.close()</code></pre> 打开的窗口，我将无法这样做。</p> <p>我知道在 <pre><code>noopener</code></pre> 方法中使用 <pre><code>window.open</code></pre> 会阻止 <pre><code>test2.html</code></pre> 访问 <pre><code>test1.html</code></pre> 但是它也会阻止我在 <pre><code>test1.html</code></pre> 关闭 <pre><code>test2.html</code></pre>。</p> <p>那么我怎样才能可靠地打开 <pre><code>window</code></pre> 并能够在将来自信地关闭它？</p> <p><strong>根据@mplungjan</strong></p>进行编辑 <p>在@mplungjan的帮助下，我做到了：</p> <pre><code>myClose = window.close; janela = window.open("https://a2eestrutural.eng.br/?fdfk","_blank","width=1000,height=400,left=600,top=20"); janela.myClose = window.myClose; </code></pre> <p>窗口打开后，我尝试执行<pre><code>janela.myClose();</code></pre>并收到此错误消息：</p> <pre><code>An attempt was made to break through the security policy of the user agent. </code></pre> <p>知道我该如何继续吗？</p> </question> <answer tick="false" vote="0"> <p>为什么要有这个代码？如果您可以控制打开的内容...</p> <p>无论如何，请在打开窗口的脚本之前尝试此操作</p> <pre><code>const myClose = window.close; const janela = window.open("http://localhost/test2.html","_blank","width=1000,height=400,left=600,top=0"); .... janela.myClose() </code></pre> </answer> </body></html>

如何使用 XML 查询功能从 XML 节点查询值

我有以下 XML 数据：声明@x XML 设置@x=' 订购我有以下 XML 数据： DECLARE @x XML SET @x='<Orders> <HeadingSection> <DocumentNameCode>Order</DocumentNameCode> <DetailSection> <LineItem LineItemNumber="10"> <ItemId>123456789</ItemId> <ItemTypeId>EN</ItemTypeId> <AdditionalProductId Qualifier="ProductId"> <Item> <ItemId>ABC</ItemId> <TypeId>SA</TypeId> </Item> </AdditionalProductId> <AdditionalProductId Qualifier="ProductId"> <Item> <ItemId>XYZ</ItemId> <TypeId>IN</TypeId> </Item> </AdditionalProductId> </LineItem> </DetailSection> <SummarySection/> </HeadingSection> </Orders>' 我已经使用了以下T-Sql脚本（必须有光标） DECLARE @xmlQuittungPOS XML DECLARE quittungCurPOS CURSOR FOR SELECT QuittungXMLPOS = T.X.query('.') FROM @x.nodes('/Orders/HeadingSection/DetailSection/LineItem') AS T(X) OPEN quittungCurPOS FETCH NEXT FROM quittungCurPOS INTO @xmlQuittungPOS WHILE @@FETCH_STATUS = 0 BEGIN INSERT INTO dbo.tempPOS ( GTIN ,edi_PIA_SA ,edi_PIA_IN ) SELECT GTIN = T.X.query('/LineItem[ItemTypeId = "BP"]').value('(/LineItem/ItemId)[1]','VARCHAR(100)') -- funktioniert / works ,edi_PIA_SA = T.X.query('/LineItem/AdditionalProductId/Item[TypeId = "SA"]').value('(/LineItem/AdditionalProductId/Item/ItemId)[1]','VARCHAR(255)') -- funktioniert nicht / doesn't work ,edi_PIA_IN = T.X.query('/LineItem/AdditionalProductId/Item[TypeId = "IN"]').value('(/LineItem/AdditionalProductId/Item/ItemId)[1]','VARCHAR(255)') -- funktioniert nicht / doesn't work FROM @xmlQuittungPOS.nodes('/LineItem') AS T(X) FETCH NEXT FROM quittungCurPOS INTO @xmlQuittungPOS END CLOSE quittungCurPOS DEALLOCATE quittungCurPOS 1.) GTIN -> 查询有效 2.) PIA_SA 和 PIA_IN -> 查询不起作用问题：我认为这是因为 '/LineItem/AdditionalProductId/Item[TypeId = "SA"]' 位于附加节点中。问题：如何获取中TypeId“SA”和“IN”的值 <AdditionalProductId Qualifier="ProductId"> <Item> <ItemId>**ABC**</ItemId> <TypeId>SA</TypeId> </Item> </AdditionalProductId> <AdditionalProductId Qualifier="ProductId"> <Item> <ItemId>**XYZ**</ItemId> <TypeId>IN</TypeId> </Item> </AdditionalProductId> with .value('(/LineItem/AdditionalProductId/Item/ItemId)[1]','VARCHAR(255)') ！处于 1 级！ -- 我知道。级别 1 上的 SA -> .value('(/LineItem/AdditionalProductId/Item/ItemId)[1]','VARCHAR(255)') 级别 2 上的 SA -> .value('(/LineItem/AdditionalProductId/Item/ItemId)[2]','VARCHAR(255)') 但我现在需要查询类型谢谢不清楚你在这里追求什么，所以我回答两者。如果您想要每个 Item 节点 1 行，那么您只需对 nodes 节点使用 Item 并获取 value 文本的 ItemId： DECLARE @xml xml = '<AdditionalProductId Qualifier="ProductId"> <Item> <ItemId>**ABC**</ItemId> <TypeId>SA</TypeId> </Item> </AdditionalProductId> <AdditionalProductId Qualifier="ProductId"> <Item> <ItemId>**XYZ**</ItemId> <TypeId>IN</TypeId> </Item> </AdditionalProductId> '; SELECT AP.I.value('(ItemId/text())[1]','varchar(15)') AS ItemId, AP.I.value('(TypeId/text())[1]','varchar(15)') AS TypeId FROM (VALUES(@XML))V(X) --To give impression it's against a table CROSS APPLY V.X.nodes ('AdditionalProductId/Item')AP(I); 但是，如果您希望每个不同的 TypeID 值各有 1 列，您可以在 XML 中进行过滤： SELECT X.AP.value('(AdditionalProductId/Item[TypeId[(text()[1])="SA"]]/ItemId/text())[1]','varchar(15)') AS ItemSA, X.AP.value('(AdditionalProductId/Item[TypeId[(text()[1])="IN"]]/ItemId/text())[1]','varchar(15)') AS ItemIN FROM @xml.nodes ('/')X(AP); --To give impression it's against a table 或者使用之前的查询并使用条件聚合： WITH Items AS( SELECT AP.I.value('(ItemId/text())[1]','varchar(15)') AS ItemId, AP.I.value('(TypeId/text())[1]','varchar(15)') AS TypeId FROM @xml.nodes ('AdditionalProductId/Item')AP(I)) SELECT MAX(CASE TypeID WHEN 'SA' THEN ItemId END) AS ItemSA, MAX(CASE TypeID WHEN 'IN' THEN ItemId END) AS ItemIN FROM Items;

在 HTML 文档中嵌入 TypeScript 代码

是否可以在网页中嵌入 TypeScript 代码？我想将 TypeScript 代码嵌入到脚本标签中，如下所示（以便它自动编译为 Javascript）： <p>是否可以在网页中嵌入 TypeScript 代码？我想将 TypeScript 代码嵌入到脚本标签中，如下所示（以便它自动编译为 Javascript）：</p> <pre><code><script type = "text/typescript"> //TypeScript code goes here </script> </code></pre> </question> <answer tick="true" vote="28"> <p>实际上有几个项目允许您使用类似的 TypeScript 代码 - <a href="https://github.com/niutech/typescript-compile" rel="noreferrer">TypeScript Compile</a>、<a href="https://github.com/ComFreek/ts-htaccess" rel="noreferrer">ts-htaccess</a>。</p> <p>这里的问题是 .ts 代码应该编译成 JavaScript - 它可以在客户端完成（速度慢；整个 TSC 也应该加载到客户端）或在服务器端完成（显然更快，而且它更快）在编译代码上利用缓存要容易得多）。</p> </answer> <answer tick="false" vote="18"> <p>这是我编写的版本，<strong>直接</strong>使用 Microsoft/TypeScript/master 的版本，因此它始终保持最新：<a href="https://github.com/basarat/typescript-script" rel="noreferrer">https://github.com/basarat/typescript-script</a></p> <p>您甚至可以将 <pre><code>ts</code></pre> 指向您可能拥有的任何其他 TypeScript 版本，它会正常工作 🌹</p> </answer> <answer tick="false" vote="6"> <p>已经为此目的开发了一个 JavaScript 库 - 它称为 <a href="https://github.com/niutech/typescript-compile" rel="noreferrer">TypeScript Compile</a>，它允许将 Typescript 嵌入到 HTML 中（如上所示。）</p> </answer> <answer tick="false" vote="0"> <p>我写这篇文章的目的是为了在浏览器中编译 TypeScript，以便我可以编写快速简单的示例来分享。</p> <p><a href="https://github.com/Sean-Bradley/text-typescript" rel="nofollow noreferrer">https://github.com/Sean-Bradley/text-typescript</a></p> <p>使用，</p> <pre><code><script type="text/typescript"> // Your TypeScript code here </script> </code></pre> <p>并包含依赖项。</p> <pre><code><script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" data-cfemail="67131e17021404150e1713275249544954">[email protected]</a>"></script> <script defer src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" data-cfemail="3743524f431a434e47524454455e4743770619041907">[email protected]</a>"></script> </code></pre> <p>一个完整的示例，您可以复制/粘贴到 HTML 文档中并在本地尝试。</p> <pre><code><!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1" /> <title>"text/typescript" example</title> <meta name="description" content="Transpiling and executing TypeScript in the browser" /> <style> body { overflow: hidden; margin: 0px; font-size: 15vw; } </style> <script type="text/typescript"> function foo(bar: string) { return "Hello " + bar; } let baz = "World!"; document.getElementById("root").innerHTML = foo(baz); </script> <script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" data-cfemail="13676a63766070617a636753263d203d20">[email protected]</a>"></script> <script defer src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" data-cfemail="ec98899498c198959c899f8f9e859c98acddc2dfc2dc">[email protected]</a>"></script> </head> <body> <div id="root"></div> </body> </html> </code></pre> <p>你可以看到它在这里、现在、今天发挥作用。</p> <p><a href="https://editor.sbcode.net/f1f4b5a73ec40283d1ddb37bb1e71f7e4e31b487" rel="nofollow noreferrer">https://editor.sbcode.net/f1f4b5a73ec40283d1ddb37bb1e71f7e4e31b487</a></p> </answer> </body></html>

更新 MyBatis 中的值列表 - SQLSyntaxErrorException

更新 MyBatis 中的值列表时出现 SQLSyntaxErrorException。我正在使用分隔符=“;”在 forecach 标签中，但我仍然收到错误。下面是我的sql查询更新 MyBatis 中的值列表时出现 SQLSyntaxErrorException。我在 forecach 标签中使用 separator=";" ，但仍然收到错误。下面是我的sql查询 <update id="updateComplianceCheckListResponse" parameterType="java.util.List"> <foreach collection="list" item="response" separator=";"> UPDATE AM_ComplianceChecklistResponse SET complianceDetailsId = #{response.complianceDetailsId}, complianceChecklistId = #{response.complianceChecklistId}, questionResponse = #{response.questionResponse}, expiryDate = #{response.expiryDate}, documentName = #{response.documentName}, comments = #{response.comments} WHERE id = #{response.id} </foreach> </update> org.apache.ibatis.exceptions.PersistenceException：更新数据库时出错。原因：java.sql.SQLSyntaxErrorException：您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，了解在“UPDATE AM_ComplianceChecklistResponse”附近使用的正确语法 SET complianceDetailsId = 1, com' at line 10 错误可能存在于 com/am/dao/managecompliance/ComplianceChecklistResponse.xml 中错误可能涉及ComplianceChecklistResponse.updateComplianceCheckListResponse-Inline 设置参数时出现错误 SQL： UPDATE AM_ComplianceChecklistResponse SETcomplianceDetailsId = ？，complianceChecklistId = ？，questionResponse = ？，expiryDate = ？，documentName = ？，comments = ？哪里 id = ？ ; UPDATE AM_ComplianceChecklistResponse SET complianceDetailsId = ?、complianceChecklistId = ?、questionResponse = ?、expiryDate = ?、documentName = ?、comments = ?哪里 id = ? 原因：java.sql.SQLSyntaxErrorException：您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，了解在“UPDATE AM_ComplianceChecklistResponse”附近使用的正确语法 SET complianceDetailsId = 1, com' at line 10 at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30) at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:196) at com.am.dao.managecompliance.ComplianceChecklistResponseDAO.updateComplianceCheckListResponse(ComplianceChecklistResponseDAO.java:50) at com.am.service.managecompliance.ComplianceChecklistResponseService.updateComplianceCheckListResponse(ComplianceChecklistResponseService.java:122) at com.am.webservice.controller.managecompliance.ManageComplianceController.updateComplianceCheckListResponse(ManageComplianceController.java:230) at com.am.webservice.controller.managecompliance.ManageComplianceController$$FastClassBySpringCGLIB$$e3100610.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) at org.springframework.aop.framework.CglibAopProxy.invokeMethod(CglibAopProxy.java:386) at org.springframework.aop.framework.CglibAopProxy.access$000(CglibAopProxy.java:85) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:704) at com.am.webservice.controller.managecompliance.ManageComplianceController$$EnhancerBySpringCGLIB$$4a5751a4.updateComplianceCheckListResponse(<generated>) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1071) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:964) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) at javax.servlet.http.HttpServlet.service(HttpServlet.java:555) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:623) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:209) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:337) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:122) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:116) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) at com.dbp.security.auth.spring.StatelessAuthenticationFilter.doFilter(StatelessAuthenticationFilter.java:55) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:221) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:186) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:354) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:267) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:481) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:670) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:390) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:928) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1794) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:833) 引起：java.sql.SQLSyntaxErrorException：您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，了解在“UPDATE AM_ComplianceChecklistResponse”附近使用的正确语法设置合规性详细信息 ID = 1, com' 在第 10 行在 com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120) 在com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException（SQLExceptionsMapping.java:122）在com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal（ClientPreparedStatement.java:916）在 com.mysql.cj.jdbc.ClientPreparedStatement.execute(ClientPreparedStatement.java:354) 在 java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0（本机方法）在 java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) 在java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在 java.base/java.lang.reflect.Method.invoke(Method.java:568) 在org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke（PreparedStatementLogger.java:59）在 jdk.proxy5/jdk.proxy5.$Proxy81.execute（来源未知）在 org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:47) 在 org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:74) 在 org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:50) 在 org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117) 在 org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76) 在 org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:194) ...省略69个常用框架修复为 <insert id="updateComplianceCheckListResponse" parameterType="java.util.List"> insert into AM_ComplianceChecklistResponse (id,complianceDetailsId,complianceChecklistId,questionResponse,expiryDate,documentName,comments) VALUES <foreach collection="list" item="response" separator="," open="(" close=")"> #{response.id}, #{response.complianceDetailsId},#{response.complianceChecklistId},#{response.questionResponse},#{response.expiryDate},#{response.documentName},#{response.comments} </foreach> on duplicate key update complianceDetailsId= VALUES(complianceDetailsId), complianceChecklistId=VALUES(complianceChecklistId), questionResponse=VALUES(questionResponse), expiryDate=VALUES(expiryDate), documentName=VALUES(documentName), comments=VALUES(comments) </insert>

如何在 C++/WinRT (WinUI3) 中将图像从内存读取到 ImageSource？

[1] 我想在 XAML 中显示 Image 控件的图像，但该图像来自字节数组。我应该怎么办？图像格式可以是JPG、BMP或PNG之一。 [1] 我想在 XAML 中显示 Image 控件的图像，但该图像来自字节数组。我该怎么办？图像格式可以是 JPG、BMP 或 PNG 之一。 <Image x:Name="img"/> void MainWindow::myButton_Click(IInspectable const&, RoutedEventArgs const&) { unsigned long long size; // iamge data size const unsigned char* buf; // image data img().Source(???); // what should I do? } [2] 我尝试了InMemoryRandomAccessStream，但没有成功。我知道在C#中使用MemoryStream很方便，但是如何在C++中实现它？另一个问题是这个方法是否也适用于JPG和PNG格式的图像？ void MainWindow::myButton_Click(IInspectable const&, RoutedEventArgs const&) { unsigned long long size; // iamge data size const unsigned char* buf; // image data winrt::Microsoft::UI::Xaml::Media::Imaging::BitmapImage bmp; winrt::Windows::Storage::Streams::InMemoryRandomAccessStream stream; // How to read data from stream? bmp.SetSource(stream); img().Source(bmp); } [3] 现在功能已经实现了，但是还有两个问题 IAsyncAction MainWindow::myButton_Click(IInspectable const&, RoutedEventArgs const&) { unsigned long long size; // iamge data size const unsigned char* buf; // image data winrt::Microsoft::UI::Xaml::Media::Imaging::BitmapImage bmp; winrt::Windows::Storage::Streams::InMemoryRandomAccessStream stream; winrt::Windows::Storage::Streams::DataWriter dw(st.GetOutputStreamAt(0ULL)); dw.WriteBytes({ buf, size }); // This is very inefficient! co_await dw.StoreAsync(); dw.Close(); bmp.SetSource(stream); img().Source(bmp); stream.Close(); } 首先，我发现DataWriter::WriteBytes()确实是在复制数据。但我认为ImageSource只需要从我的buf中读取即可，不需要在读取之前将整个图像完全复制到流中。也许是类似MemoryView的东西，我这样想是不是错了？其次，DataWriter和InMemoryRandomAccessStream的Close()应该在哪里调用？ BitmapImage需要释放内存吗？这里有一个异步函数，我不知道应该写在哪里 [4] 根据IInspectable，我尝试了SHCreatMemStream并搜索了大量信息以提出另一个解决方案。目前的问题是，与方法[3]同样可行，但仍然会出现内存分配问题。 #include "Shlwapi.h" #include "shcore.h" #pragma comment(lib, "shlwapi.lib") void MainWindow::myButton_Click(IInspectable const&, RoutedEventArgs const&) { unsigned long long size; // iamge data size const unsigned char* buf; // image data winrt::Microsoft::UI::Xaml::Media::Imaging::BitmapImage bmp; IStream* stream{ SHCreateMemStream(buf, size) }; // Copying takes a lot of time static const GUID guidIRandomAccessStream = { 0x905a0fe1, 0xbc53, 0x11df, { 0x8c, 0x49, 0x00, 0x1e, 0x4f, 0xc6, 0x86, 0xda } }; winrt::Windows::Storage::Streams::IRandomAccessStream pRas{ }; CreateRandomAccessStreamOverStream(stream, BSOS_OPTIONS::BSOS_DEFAULT, guidIRandomAccessStream, (void**)&pRas); bmp.SetSource(stream); img().Source(bmp); } 通过性能测试，发现CreateRandomAccessStreamOverStream的时间是一致的，但是SHCreateMemStream消耗的时间与图像大小成正比。可以得出，SHCreateMemStream中创建流的过程也涉及到内存的复制。我对Windows编程中的Stream不是特别熟悉。创建流的过程一定会涉及到内存复制吗？从内存加载图像可以避免额外的开销吗？还有没有类似MemoryStreamView的结构来替代吗？还有一个问题，我知道新的图像肯定需要内存存储。 BitmapImage设置Stream为Source会接管Stream占用的内存吗？ Image控件设置BitmapImage作为Source会接管BitmapImage占用的内存吗？如果是这样的话，我可以接受Stream分配新的内存，否则仍然是一个效率问题。谢谢！！！！！！！使用Stream已经彻底解决了这个问题。如前四期所述。至于附加问题： ★1 使用 CreatStreamOnHGlobal 而不是 SHCreatMemStream。因为SHCreatMemStream在调用过程中会对传入的内存块参数进行另一次内存复制。 CreatStreamOnHGlobal 创建流后不执行内存复制。您可以先通过GlobalAlloc分配内存，写入所需的图像数据，然后调用CreatStreamOnHGlobal，无需任何时间开销。另外，可以将CreatStreamOnHGlobal的第二个参数设置为true，自动释放GlobalAlloc分配的内存。通过进程内存监控，我发现对于同一个程序，使用CreatStreamOnHGlobal的速度是SHCreatMemStream的两倍，并且不会导致内存泄漏。 ★2 创建的Stream需要调用Release方法减少一个引用。 IRandomAccessStream作为局部变量，会自动析构，无需主动释放。并且BitmapImage还管理一部分引用，这些引用在离开作用域后被释放。通过测试COM对象上Release方法的返回值，发现整个程序结束后引用计数又回到了0

错误：在此 BlocBuilder<InternetBloc> Widget<InternetBloc, InternetState> 上方找不到正确的提供程序

我在尝试将 flutter_bloc 集成到 flutter 项目中时遇到错误。错误：在此 BlocBuilder 上方找不到正确的 Provider 我在尝试将 flutter_bloc 集成到 flutter 项目中时遇到错误。错误：在此 BlocBuilder Widget 上方找不到正确的提供者这是我正在使用的代码示例。 internet_state.dart abstract class InternetState{} class InitialInternetState extends InternetState{} class LostConnectionInternetState extends InternetState{} class GainConnectionInternetState extends InternetState{} internet_event.dart abstract class InternetEvent{} class LostConnectionEvent extends InternetEvent{} class GainConnectionEvent extends InternetEvent{} internet_bloc.dart class InternetBloc extends Bloc<InternetEvent, InternetState>{ final Connectivity _connectivity = Connectivity(); StreamSubscription? streamSubscription; InternetBloc() : super(InitialInternetState()){ on<GainConnectionEvent>((event, emit) => emit(GainConnectionInternetState())); on<LostConnectionEvent>((event, emit) => emit(LostConnectionInternetState())); _connectivity.onConnectivityChanged.listen((event) { if(event == ConnectivityResult.mobile || event == ConnectivityResult.wifi){ add(GainConnectionEvent()); } else { add(LostConnectionEvent()); } }); } @override Future<void> close() { streamSubscription?.cancel(); return super.close(); } } main.dart class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( title: 'Flutter Demo', theme: ThemeData( colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple), useMaterial3: true, ), home: const MyHomePage(title: 'Flutter Demo Home Page'), ); } } class MyHomePage extends StatelessWidget { const MyHomePage({super.key, required this.title}); final String title; @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: Text(title),), body: SafeArea( child: Center(child: BlocBuilder<InternetBloc, InternetState>( builder: (context, state) { return const Text("hello"); }, )), ),); } } 我明白了。 ======== 小部件库捕获异常====================================== =================== 构建 MediaQuery(MediaQueryData(size: Size(392.7, 783.3), devicePixelRatio: 2.8, textScaler: noscaling, platformBrightness: Brightness.light, padding: EdgeInsets.zero, viewPadding: EdgeInsets.zero, viewInsets: EdgeInsets 时抛出以下 ProviderNotFoundException。零，systemGestureInsets：EdgeInsets（29.8，24.0，29.8，8.0），alwaysUse24HourFormat：假，accessibleNavigation：假，highContrast：假，onOffSwitchLabels：假，disableAnimations：假，invertColors：假，boldText：假，navigationMode：传统，gestureSettings：DeviceGestureSettings （touchSlop：8.0），显示功能：[]））：错误：无法在此 BlocBuilder Widget 之上找到正确的提供程序发生这种情况是因为您使用了不包含提供程序的 BuildContext 你的选择。有以下几种常见场景：您在main.dart中添加了一个新的提供程序并执行了热重载。要修复此问题，请执行热重启。您尝试阅读的提供商处于不同的路线。提供商具有“范围”。因此，如果您在路线中插入提供者，那么其他路线将无法访问该提供商。您使用了 BuildContext，它是您尝试读取的提供程序的祖先。确保 BlocBuilder 位于您的 MultiProvider/Provider 下。当您创建提供程序并尝试立即读取它时，通常会发生这种情况。例如，代替： Widget build(BuildContext context) { return Provider<Example>( create: (_) => Example(), // Will throw a ProviderNotFoundError, because `context` is associated // to the widget that is the parent of `Provider<Example>` child: Text(context.watch<Example>().toString()), ); } 考虑使用builder，如下所示： Widget build(BuildContext context) { return Provider<Example>( create: (_) => Example(), // we use `builder` to obtain a new `BuildContext` that has access to the provider builder: (context, child) { // No longer throws return Text(context.watch<Example>().toString()); } ); } 如果这些解决方案都不起作用，请考虑在 StackOverflow 上寻求帮助： https://stackoverflow.com/questions/tagged/flutter The relevant error-causing widget was: SafeArea SafeArea:file:///Users/../Projects/flutterTest/bloc_test/lib/main.dart:37:13 When the exception was thrown, this was the stack: #0 Provider._inheritedElementOf (package:provider/src/provider.dart:343:7) #1 Provider.of (package:provider/src/provider.dart:293:30) #2 ReadContext.read (package:provider/src/provider.dart:649:21) #3 _BlocBuilderBaseState.initState (package:flutter_bloc/src/bloc_builder.dart:130:36) #4 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5602:55) #5 ComponentElement.mount (package:flutter/src/widgets/framework.dart:5447:5) ... Normal element mounting (4 frames) #9 Element.inflateWidget (package:flutter/src/widgets/framework.dart:4326:16) #10 Element.updateChild (package:flutter/src/widgets/framework.dart:3831:20) #11 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #12 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #13 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #14 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #15 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:6743:14) #16 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #17 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #18 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #19 StatelessElement.update (package:flutter/src/widgets/framework.dart:5547:5) #20 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #21 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #22 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #23 StatelessElement.update (package:flutter/src/widgets/framework.dart:5547:5) #24 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #25 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #26 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #27 StatelessElement.update (package:flutter/src/widgets/framework.dart:5547:5) #28 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #29 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #30 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #31 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #32 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #33 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #34 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #35 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #36 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #37 Element.updateChildren (package:flutter/src/widgets/framework.dart:3964:32) #38 MultiChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:6896:17) #39 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #40 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #41 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #42 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #43 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #44 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #45 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #46 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #47 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #48 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #49 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #50 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #51 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #52 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #53 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #54 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #55 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #56 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #57 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #58 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #59 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #60 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #61 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #62 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #63 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:6743:14) #64 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #65 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #66 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #67 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #68 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #69 SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:6743:14) #70 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #71 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #72 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #73 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #74 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #75 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #76 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #77 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #78 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #79 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #80 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #81 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #82 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #83 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #84 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #85 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #86 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #87 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #88 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #89 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #90 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #91 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #92 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #93 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #94 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #95 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #96 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #97 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #98 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #99 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #100 ProxyElement.update (package:flutter/src/widgets/framework.dart:5800:5) #101 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #102 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #103 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5634:11) #104 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #105 StatefulElement.update (package:flutter/src/widgets/framework.dart:5657:5) #106 Element.updateChild (package:flutter/src/widgets/framework.dart:3815:15) #107 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5496:16) #108 Element.rebuild (package:flutter/src/widgets/framework.dart:5187:7) #109 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2895:19) #110 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:984:21) #111 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:457:5) #112 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1325:15) #113 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1255:9) #114 SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:978:7) #118 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12) (elided 3 frames from class _Timer and dart:async-patch) ==================================================================================================== 我不想使用像 MultiProvider 这样的全局提供程序。您应该在某处创建 InternetBloc 并提供它。 MultiProvider 本身并不是全局的，它只是多个。更多信息在这里：https://bloclibrary.dev/#/flutterbloccoreconcepts?id=blocprovider 所以，如果您不想使用全局提供程序，它将看起来像这样： class MyHomePage extends StatelessWidget { const MyHomePage({super.key, required this.title}); final String title; @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text(title), ), body: SafeArea( child: Center( child: BlocProvider<InternetBloc>( create: ( context) => InternetBloc(), child: BlocBuilder<InternetBloc, InternetState>( builder: (context, state) { return const Text("hello"); }, ), ), ), ), ); } } 要使用 BlocBuilder，您需要在 Widget 树中放置一个 BlocProvider。最佳实践是将其放置得尽可能深。在您的情况下，只需将 BlocProvider 放在 BlocBuilder 之上。此外 MultiProvider / MultiBlocProvider 不是全局 Provider。它只是一个提供多个 Provider/BlocProvider 的便捷小部件。 class MyHomePage extends StatelessWidget { const MyHomePage({super.key, required this.title}); final String title; @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text(title), ), body: SafeArea( child: Center( // Now everything below that can access the InternetBloc child: BlocProvider<InternetBloc>( create: (_) => InternetBloc(), child: BlocBuilder<InternetBloc, InternetState>( builder: (context, state) { return const Text("hello"); }, ), ), ), ), ); } }

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