constructor-exception 相关问题

Mockery\Exception\NoMatchingExpectationException：找不到 Mockery_1_::make 的匹配处理程序

我编写了此测试，返回以下错误： Mockery\Exception\NoMatchingExpectationException：没有匹配的处理程序找到了 Mockery_1_My_Class::make(array('valid_until'=>...

未捕获错误：未找到“Instamojo\Exception\InstamojoException”类

$authType = "应用程序/用户"; $api = Instamojo\Instamojo::init($authType,[ “client_id”=>“XXXXXQAZ”， “client_secret”=>“XXXXQWE”， ]，真的）; ...

获取 NullPointerException：“无法调用“ParkingSpace.getSpaceNum()”，因为“pl.parkingLot[5]”为空”？

我正在用Java开发一个停车场项目，当我运行我的程序时，我收到以下错误消息： Exception in thread "main" java.lang.NullPointerException: Cannot invoke...

Windows 7 无法创建 SSL/TLS 安全通道。”} System.Net.WebException

我正在运行 Windows 7 64 位专业版并尝试编写 RSS Feed 阅读器这是错误消息 - $Exception {“请求被中止：无法创建 SSL/TLS 安全通道。”} System.Net。

错误：cvc-elt.1.a：找不到元素“beans”的声明

添加此代码时，出现此错误，我尝试将 beans:beans 添加到标记中，但随后出现相同的错误，请帮我解决此问题添加此代码时，出现此错误，我尝试将 beans:beans 添加到标签中，但随后出现相同的错误，请帮我解决这个问题 <?xml version="1.0" encoding="UTF-8"?> <beans xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <bean id="testBean" class="alishev.spring.demo.TestBean"> <constructor-arg value="Neil"/> </bean> </beans> 您拥有 xmlns:beans="http://www.springframework.org/schema/beans"，这意味着您需要为该命名空间中的所有标签添加前缀 beans:。从 :beans 中删除 xmlns:beans="http://www.springframework.org/schema/beans"，这样您的 XML 应如下所示 <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <bean id="testBean" class="alishev.spring.demo.TestBean"> <constructor-arg value="Neil"/> </bean> </beans>

观察子组件中的@Output事件发射器？

应该如何在子组件中使用/观察父 @Output() 事件发射器？例如，在此演示中，子组件使用 @Output onGreetingChange，如下所示：应该如何在子组件中使用/观察父级@Output()事件发射器？例如在这个演示中子组件使用@Output onGreetingChange，如下所示： <app-greeting [greeting]="onGreetingChange | async"></app-greeting> 如果 onGreetingChange 在 AfterViewInit 生命周期钩子中发出，这将起作用。 ngAfterViewInit() { this.onGreetingChange.emit('Hola'); } 但是这会产生 ExpressionChangedAfterItHasBeenCheckedError 错误。有没有办法让它工作而不产生错误？我尝试在 constructor 和 OnInit 中发射。想法？您可以使用 change detection 手动触发 detectChanges() ngAfterViewInit() { this.onGreetingChange.emit('Hola'); this.cdr.detectChanges(); } 堆栈闪电战

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; } }

如何防止点击时嵌套 React 组件中的事件冒泡？

这是一个基本组件。和都有 onClick 函数。我只想触发上的 onClick，而不是。我怎样才能实现这个目标？我玩过这是一个基本组件。 <ul> 和 <li> 都有 onClick 函数。我只想触发 <li> 上的 onClick，而不是 <ul>。我怎样才能实现这个目标？我尝试过 e.preventDefault()、e.stopPropagation()，但无济于事。 class List extends React.Component { constructor(props) { super(props); } handleClick() { // do something } render() { return ( <ul onClick={(e) => { console.log('parent'); this.handleClick(); }} > <li onClick={(e) => { console.log('child'); // prevent default? prevent propagation? this.handleClick(); }} > </li> </ul> ) } } // => parent // => child 我也有同样的问题。我发现 stopPropagation did 有效。我会将列表项拆分为一个单独的组件，如下所示： class List extends React.Component { handleClick = e => { // do something } render() { return ( <ul onClick={this.handleClick}> <ListItem onClick={this.handleClick}>Item</ListItem> </ul> ) } } class ListItem extends React.Component { handleClick = e => { e.stopPropagation(); // <------ Here is the magic this.props.onClick(); } render() { return ( <li onClick={this.handleClick}> {this.props.children} </li> ) } } React 使用事件委托和文档上的单个事件侦听器来处理冒泡事件，例如本例中的“单击”，这意味着不可能停止传播；当您在 React 中与真实事件交互时，真实事件已经传播。 React 的合成事件上的 stopPropagation 是可能的，因为 React 在内部处理合成事件的传播。 stopPropagation: function(e){ e.stopPropagation(); e.nativeEvent.stopImmediatePropagation(); } 关于 DOM 事件的顺序：CAPTURING vs BUBBLING 事件传播有两个阶段。这些被称为 “捕获” 和 “冒泡”。 | | / \ ---------------| |----------------- ---------------| |----------------- | element1 | | | | element1 | | | | -----------| |----------- | | -----------| |----------- | | |element2 \ / | | | |element2 | | | | | ------------------------- | | ------------------------- | | Event CAPTURING | | Event BUBBLING | ----------------------------------- ----------------------------------- 首先发生捕获阶段，然后是冒泡阶段。当您使用常规 DOM api 注册事件时，默认情况下事件将成为冒泡阶段的一部分，但这可以在事件创建时指定 // CAPTURING event button.addEventListener('click', handleClick, true) // BUBBLING events button.addEventListener('click', handleClick, false) button.addEventListener('click', handleClick) 在React中，冒泡事件也是你默认使用的。 // handleClick is a BUBBLING (synthetic) event <button onClick={handleClick}></button> // handleClick is a CAPTURING (synthetic) event <button onClickCapture={handleClick}></button> 让我们看一下handleClick回调（React）： function handleClick(e) { // This will prevent any synthetic events from firing after this one e.stopPropagation() } function handleClick(e) { // This will set e.defaultPrevented to true // (for all synthetic events firing after this one) e.preventDefault() } 我在这里没有看到提到的替代方案如果您在所有事件中调用 e.preventDefault()，您可以检查事件是否已被处理，并防止再次处理它： handleEvent(e) { if (e.defaultPrevented) return // Exits here if event has been handled e.preventDefault() // Perform whatever you need to here. } 关于合成事件和原生事件的区别，请参阅React文档：https://reactjs.org/docs/events.html 这是防止单击事件前进到下一个组件然后调用 yourFunction 的简单方法。 <Button onClick={(e)=> {e.stopPropagation(); yourFunction(someParam)}}>Delete</Button> 这不是 100% 理想，但如果在儿童中传递 props 太痛苦 -> 儿童时尚或为此目的创建 Context.Provider/Context.Consumer just），你正在处理另一个库，它有自己的处理程序，它在您的处理程序之前运行，您也可以尝试： function myHandler(e) { e.persist(); e.nativeEvent.stopImmediatePropagation(); e.stopPropagation(); } 据我了解，event.persist方法可以防止对象立即被扔回React的SyntheticEvent池中。因此，当你伸手去拿 React 中传递的 event 时，它实际上并不存在！这种情况发生在孙子中，因为 React 在内部处理事情的方式是首先检查父进程是否有 SyntheticEvent 处理程序（特别是如果父进程有回调）。只要您不调用 persist 来创建大量内存以继续创建诸如 onMouseMove 之类的事件（并且您没有创建某种 Cookie Clicker 游戏，例如 Grandma's Cookies），就应该完全没问题！另请注意：偶尔阅读他们的 GitHub，我们应该密切关注 React 的未来版本，因为他们可能最终会解决一些问题，因为他们似乎打算在编译器中折叠 React 代码/转译器。如果您希望发生嵌套元素中的操作而不是父元素中的操作，那么，您可以从父元素的操作处理程序中检查目标的类型，然后基于该类型执行操作，即，如果目标是我们的嵌套元素，我们什么也不做。否则两个处理程序都会被调用。 // Handler of the parent element. Let's assume the nested element is a checkbox function handleSingleSelection(e) { if(e.target.type !== 'checkbox') { // We do not do anything from the // parent handler if the target is a checkbox ( our nested element) // Note that the target will always be the nested element dispatch(lineSelectionSingle({ line })) } } 我在 event.stopPropagation() 工作时遇到问题。如果您也这样做，请尝试将其移动到单击处理程序函数的顶部，这就是我需要做的来阻止事件冒泡。示例函数： toggleFilter(e) { e.stopPropagation(); // If moved to the end of the function, will not work let target = e.target; let i = 10; // Sanity breaker while(true) { if (--i === 0) { return; } if (target.classList.contains("filter")) { target.classList.toggle("active"); break; } target = target.parentNode; } } 您可以通过检查事件目标来避免事件冒泡。例如，如果您将输入嵌套到 div 元素，其中有单击事件的处理程序，并且您不想处理它，则单击输入时，您可以将 event.target 传递到您的处理程序中，并检查处理程序应该是根据目标的属性执行。例如，您可以检查 if (target.localName === "input") { return}。所以，这是一种“避免”处理程序执行的方法解决此问题的另一种方法可能是在子级上设置 onMouseEnter 和 onMouseLeave 事件。（您的 < li > 标签）每当鼠标悬停在子级上时，您都可以设置一个特定的状态，以阻止父级执行 onClick 函数内容。比如： class List extends React.Component { constructor(props) { super(props) this.state.overLi = false } handleClick() { // do something } render() { return ( <ul onClick={(e) => { if (!this.state.overLi) { console.log("parent") this.handleClick() } }} > <li onClick={(e) => { console.log("child") // prevent default? prevent propagation? this.handleClick() }} onMouseEnter={() => this.setState({ overLi: true, }) } onMouseLeave={() => this.setState({ overLi: false, })} ></li> </ul> ) } } 我进行了很多搜索，但没有设法使用 e.stopPropagation() 为我的上下文实现任何解决方案您可以验证点击的元素是否是预期的元素。例如： class List extends React.Component { constructor(props) { super(props); } handleClick(e) { if(e.target.className==='class-name'){ // do something } } render() { return ( <ul {/* Replace this with handleClick */} onClick={(e) => { console.log('parent'); this.handleClick(); }} <li onClick={(e) => { console.log('child'); // prevent default? prevent propagation? this.handleClick(); }} </li> </ul> ) } } 执行此操作的新方法更加简单，并且会节省您一些时间！只需将事件传递到原始点击处理程序并调用 preventDefault();。 clickHandler(e){ e.preventDefault(); //Your functionality here }

如何以 Svelte 方式设置导出和开槽零件的样式？

Svelte slot 的功能是否像 vanilla-js/dom 一样（我似乎无法让它工作）。在 html/js 中我可以这样做：身体{颜色：红色;} /* 从外部设置暴露部分的样式 */ ...</desc> <question vote="0"> <p>Svelte <pre><code>slot</code></pre>的功能是否像 vanilla-js/dom 一样（我似乎无法让它工作）。</p> <p>在 html/js 中我可以做：</p> <p></p><div data-babel="false" data-lang="js" data-hide="false" data-console="true"> <div> <pre><code><style> body {color: red;} /* style exposed part from outside */ my-element::part(header) {color: green;} </style> <h1>Hello World</h1> <my-element> <div slot="header"><strong>Header</strong></div> <div slot="body">Body</div> </my-element> <script> customElements.define('my-element', class extends HTMLElement { constructor() { super(); const shadowRoot = this.attachShadow({mode: 'open'}); shadowRoot.innerHTML = ` <style> .container { border: solid 1px blue; padding: 5px; position: relative; &:after { content: "my-element"; display: block; position: absolute; bottom: -.5em; right: 5px; border: inherit; background-color: white; padding: inherit; } } /* style inserted/slotted part from inside */ [part="body"] ::slotted(div) { background-color: lightyellow; } </style> <div class="container"> <header part="header"><slot name="header"></slot></header> <hr> <div part="body"><slot name="body"></slot></div> </div> `; } }); </script></code></pre> </div> </div> <p></p> <p>其中 <pre><code>h1</code></pre> 的全局样式为红色，标有 <pre><code>part="header"</code></pre> 的元素从外部设置为绿色，插入 <pre><code>slot="body"</code></pre> 的内容从内部（shadow dom）设置为绿色有浅黄色背景。</p> <p>我不知道如何在 svelte 中执行任何这种（受控）跨界样式？（例如，当使用 <pre><code>AppShell::part(content)</code></pre> 时，我收到错误：</p> <pre><code>[plugin:vite-plugin-svelte] C:/srv/svelte/yoda5/src/routes/+layout.svelte:23:18 Expected a valid CSS identifier C:/srv/svelte/yoda5/src/routes/+layout.svelte:23:18 21 | 22 | <style> 23 | AppShell::part(content) { | ^ </code></pre> </question> <answer tick="false" vote="0"> <p>这里有关于<a href="https://learn.svelte.dev/tutorial/slots" rel="nofollow noreferrer">老虎机的课程</a>。最好参考该工具的文档。 Svelte 的学习网站非常棒。</p> <pre><code>// Slotted component, say Test.svelte. <div class="private-parent"> <slot /> </div> <style> div.private-parent { color: blue; } </style> </code></pre> <p>然后，您使用该组件：</p> <pre><code><script> import Test from './Test.svelte'; </script> <Test>  <p class="outside-style">Hello!</p> </Test> <style> p.outside-style { color: darkred; } </style> </code></pre> </answer> </body></html>

ng-bootstrap 滚动间谍在没有高度的情况下无法工作？

我在我的项目中使用 ng-bootstrap [ngbScrollSpy] 指令，如文档中所述，但它不起作用 - 滚动时活动项目不会改变。我的代码如下：我在我的项目中使用 ng-bootstrap [ngbScrollSpy] 指令，如文档中所述，但它不起作用 - 滚动时活动项目不会改变。我的代码如下： <div> <div class="sticky-top"> <ul class="nav menu-sidebar"> <li > <a [ngbScrollSpyItem]="[spy, 'about']">About</a> </li> <li > <a [ngbScrollSpyItem]="spy" fragment="schedule">Schedule</a> </li> <li > <a [ngbScrollSpyItem]="spy" fragment="hotel">Information about the hotel</a> </li> </ul> </div> <div ngbScrollSpy #spy="ngbScrollSpy" > <section ngbScrollSpyFragment="about"> <h3>About</h3> <p>{{some long long text and content}}</p> </section> <section ngbScrollSpyFragment="schedule"> <h3>Schedule</h3> <p>{{some long long text and content}}</p> </section> <section ngbScrollSpyFragment="hotel"> <h3>Information about the hotel</h3> <p>{{some long long text and content}}</p> </section> </div> </div> 我在这个 stackoverflow 问题中看到，我的问题是我没有向我的 div 提供 height，这是事实。但我的滚动间谍部分遍布整个页面，而不是一个小 div，（导航本身是 sticky-top）。所以我不能给它高度。我知道有替代方法 - 刷新窗口滚动上的滚动间谍，但我没有找到可以帮助我的正确代码。你能解决我的问题吗？为我提供刷新滚动间谍的代码/给我有关高度的提示/帮助我找到另一个相应的元素。非常感谢！附上 stackblitz 演示的链接注意：我使用来自 @ng-bootstrap/ng-bootstrap 的 NgbScrollSpy （我想它是非常相似的库）我做什么：我将所有内容（包括导航）包装在中 <div class="wrapper" ngbScrollSpy #spy="ngbScrollSpy" rootMargin="2px" [threshold]="1.0" > <div class="sticky-top pt-4 pb-4 bg-white"> ..here the navigation... </div> ..here the sections... <section ngbScrollSpyFragment="about"> </section> //the last I use margin-bottom:2rem; <section ngbScrollSpyFragment="hotel" style="margin-bottom:10rem" </section> </div> 见“门槛”。这表明“更改”活动片段应该可见的百分比（1 是 100%）包装类 .wrapper{ height:100%; position: absolute; top:0; } 我使用强制链接的类别 //remove all the class for the link a{ color:black; text-decoration:none; padding:8px 16px; } a.custom-active{ color:white; background-color:royalblue } 以及我使用的每个链接 <a [class.custom-active]="spy.active=='about'">About</a> 嗯，问题是如何“滚动到”。 “链接”应该作为链接使用。第一个是指示“路由器”应该考虑“碎片” 如果我们的组件是独立组件，我们需要使用提供者，provideRouter bootstrapApplication(App, { providers: [ provideRouter([], withInMemoryScrolling({anchorScrolling:'enabled'})), ] }) 然后，我们需要考虑到我们的页面确实没有滚动，div“包装器”是谁拥有滚动。因此，我们订阅 router.events，当事件有“锚点”时，我们滚动“包装器”div constructor(router: Router) { router.events.pipe(filter((e:any) => e.anchor)).subscribe((e: any) => { (document.getElementById('wrapper') as any).scrollTop+= (document.getElementById(e.anchor)?.getBoundingClientRect().top||0) -72; //<--this is the offset }); } 在这个stactblitz中你有一个有效的例子

显示输入类型日期的占位符文本

占位符不适用于直接输入类型日期和日期时间本地。占位符不适用于直接输入类型 date 和 datetime-local。 <input type="date" placeholder="Date" /> <input type="datetime-local" placeholder="Date" /> 该字段在桌面上显示 mm/dd/yyy，而在移动设备上则不显示任何内容。如何显示 Date 占位符文本？使用onfocus="(this.type='date')"，例如： <input required="" type="text" class="form-control" placeholder="Date" onfocus="(this.type='date')"/> 使用onfocus和onblur...这是一个例子： <input type="text" placeholder="Birth Date" onfocus="(this.type='date')" onblur="if(this.value==''){this.type='text'}"> 在这里，我尝试了 data 元素中的 input 属性。并使用 CSS 应用所需的占位符 <input type="date" name="dob" data-placeholder="Date of birth" required aria-required="true" /> input[type="date"]::before { content: attr(data-placeholder); width: 100%; } /* hide our custom/fake placeholder text when in focus to show the default * 'mm/dd/yyyy' value and when valid to show the users' date of birth value. */ input[type="date"]:focus::before, input[type="date"]:valid::before { display: none } <input type="date" name="dob" data-placeholder="Date of birth" required aria-required="true" /> 希望这有帮助 <input type="text" placeholder="*To Date" onfocus="(this.type='date')" onblur="(this.type='text')" > 这段代码对我有用。只需使用这个即可对于 Angular 2，你可以使用这个指令 import {Directive, ElementRef, HostListener} from '@angular/core'; @Directive({ selector: '[appDateClick]' }) export class DateClickDirective { @HostListener('focus') onMouseFocus() { this.el.nativeElement.type = 'date'; setTimeout(()=>{this.el.nativeElement.click()},2); } @HostListener('blur') onMouseBlur() { if(this.el.nativeElement.value == ""){ this.el.nativeElement.type = 'text'; } } constructor(private el:ElementRef) { } } 并像下面一样使用它。 <input appDateClick name="targetDate" placeholder="buton name" type="text"> 对于 React，你可以这样做。 const onDateFocus = (e) => (e.target.type = "datetime-local"); const onDateBlur = (e) => (e.target.type = "text"); . . . <input onFocus={onDateFocus} onBlur={onDateBlur} type="text" placeholder="Event Date" /> 我是这样做的： var dateInputs = document.querySelectorAll('input[type="date"]'); dateInputs.forEach(function(input) { input.addEventListener('change', function() { input.classList.add('no-placeholder') }); }); input[type="date"] { position: relative; } input[type="date"]:not(.has-value):before { position: absolute; left: 10px; top: 30%; color: gray; background: var(--primary-light); content: attr(placeholder); } .no-placeholder:before{ content:''!important; } <input type="date" name="my-date" id="my-date" placeholder="My Date"> 现代浏览器使用 Shadow DOM 来方便输入日期和日期时间。因此，除非浏览器出于某种原因选择回退到 text 输入，否则不会显示占位符文本。您可以使用以下逻辑来适应这两种情况： ::-webkit-calendar-picker-indicator { @apply hidden; /* hide native picker icon */ } input[type^='date']:not(:placeholder-shown) { @apply before:content-[attr(placeholder)]; @apply sm:after:content-[attr(placeholder)] sm:before:hidden; } input[type^='date']::after, input[type^='date']::before { @apply text-gray-500; } 我使用了 Tailwind CSS 语法，因为它很容易理解。让我们一点一点地分解它： ::-webkit-calendar-picker-indicator { @apply hidden; /* hide native picker icon */ } 使用其 Shadow DOM 伪元素选择器隐藏本机选择器图标（通常是日历）。 input[type^='date']:not(:placeholder-shown) { @apply before:content-[attr(placeholder)]; @apply sm:after:content-[attr(placeholder)] sm:before:hidden; } 选择所有未显示占位符的 date 和 datetime-local 输入，并且：默认使用 placeholder 伪元素显示输入 ::before 文本在小屏幕及以上屏幕上切换为使用 ::after 伪元素 input[type^='date']::after, input[type^='date']::before { @apply text-gray-500; } 设置 ::before 和 ::after 伪元素的样式。

通过更少的 Java API 调用来映射 Google 云端硬盘内容的有效方法

大家好，我有一个代码，用于列出共享驱动器中存在的文件（以便稍后下载并创建相同的文件夹路径）目前我做这样的事情：哈希映射大家好，我有一个代码，用于列出共享驱动器中存在的文件（以便稍后下载并创建相同的文件夹路径）目前我正在做这样的事情： HashMap<String, Strin> foldersPathToID = new HashMap<>(); //searching all folders first saving their IDs searchAllFoldersRecursive(folderName.trim(), driveId, foldersPathToID); //then listing files in all folders HashMap<String, List<File>> pathFile = new HashMap<>(); for (Entry<String, String> pathFolder : foldersPathToID.entrySet()) { List<File> result = search(Type.FILE, pathFolder.getValue()); if (result.size() > 0) { String targetPathFolder = pathFolder.getKey().trim(); pathFile.putIfAbsent(targetPathFolder, new ArrayList<>()); for (File file : result) { pathFile.get(targetPathFolder).add(file); } } } 递归方法在哪里： private static void searchAllFoldersRecursive(String nameFold, String id, HashMap<String, String> map) throws IOException, RefreshTokenException { map.putIfAbsent(nameFold, id); List<File> result; result = search(Type.FOLDER, id); // dig deeper if (result.size() > 0) { for (File folder : result) { searchAllFoldersRecursive(nameFold + java.io.File.separator + normalizeName(folder.getName()), folder.getId(), map); } } } 搜索功能是： private static List<com.google.api.services.drive.model.File> search(Type type, String folderId) throws IOException, RefreshTokenException { String nextPageToken = "go"; List<File> driveFolders = new ArrayList<>(); com.google.api.services.drive.Drive.Files.List request = service.files() .list() .setQ("'" + folderId + "' in parents and mimeType" + (type == Type.FOLDER ? "=" : "!=") + "'application/vnd.google-apps.folder' and trashed = false") .setPageSize(100).setFields("nextPageToken, files(id, name)"); while (nextPageToken != null && nextPageToken.length() > 0) { try { FileList result = request.execute(); driveFolders.addAll(result.getFiles()); nextPageToken = result.getNextPageToken(); request.setPageToken(nextPageToken); return driveFolders; } catch (TokenResponseException tokenError) { if (tokenError.getDetails().getError().equalsIgnoreCase("invalid_grant")) { log.err("Token no more valid removing it Please retry"); java.io.File cred = new java.io.File("./tokens/StoredCredential"); if (cred.exists()) { cred.delete(); } throw new RefreshTokenException("Creds invalid will retry re allow for the token"); } log.err("Error while geting response with token for folder id : " + folderId, tokenError); nextPageToken = null; } catch (Exception e) { log.err("Error while reading folder id : " + folderId, e); nextPageToken = null; } } return new ArrayList<>(); } 我确信有一种方法可以通过很少的 api 调用（甚至可能是一个调用？）对每个文件（使用文件夹树路径）进行正确的映射，因为在我的版本中，我花了很多时间进行调用 service.files().list().setQ("'" + folderId+ "' in parents and mimeType" + (type == Type.FOLDER ? "=" : "!=") + "'application/vnd.google-apps.folder' and trashed = false").setPageSize(100).setFields("nextPageToken, files(id, name)"); 每个子文件夹至少一次......并且递归搜索所有内容需要很长时间。最后，映射比下载本身花费的时间更多...... 我搜索了文档，也在此处搜索，但没有找到任何内容来列出具有一个库的所有驱动器调用任何想法？我想使用专用的 java API 来获取共享 GoogleDrive 中的所有文件及其相对路径，但调用次数尽可能少。提前感谢您的时间和答复我建议您使用高效的数据结构和逻辑来构建文件夹树并将文件映射到其路径，如下所示 private static void mapDriveContent(String driveId) throws IOException { // HashMap to store folder ID to path mapping HashMap<String, String> idToPath = new HashMap<>(); // HashMap to store files based on their paths HashMap<String, List<File>> pathToFile = new HashMap<>(); // Fetch all files and folders in the drive List<File> allFiles = fetchAllFiles(driveId); // Build folder path mapping and organize files for (File file : allFiles) { String parentId = (file.getParents() != null && !file.getParents().isEmpty()) ? file.getParents().get(0) : null; String path = buildPath(file, parentId, idToPath); if (file.getMimeType().equals("application/vnd.google-apps.folder")) { idToPath.put(file.getId(), path); } else { pathToFile.computeIfAbsent(path, k -> new ArrayList<>()).add(file); } } // Now, pathToFile contains the mapping of paths to files // Your logic to handle these files goes here } private static List<File> fetchAllFiles(String driveId) throws IOException { // Implement fetching all files and folders here // Make sure to handle pagination if necessary // ... } private static String buildPath(File file, String parentId, HashMap<String, String> idToPath) { // Build the file path based on its parent ID and the idToPath mapping // ... }

SecurityException：不允许启动服务Intent { act=com.google.android.c2dm.intent.REGISTER pkg=com.google.android.gms （有额外功能）}

我尝试从 Google 获取我的 GCM 注册 ID。我的代码：字符串SENDER_ID =“722*****53”; /** * 向 GCM 服务器异步注册应用程序。 * * 存储注册信息... 我尝试从 Google 获取我的 GCM 注册 ID。我的代码： String SENDER_ID = "722******53"; /** * Registers the application with GCM servers asynchronously. * <p> * Stores the registration ID and the app versionCode in the application's * shared preferences. */ private void registerInBackground() { new AsyncTask<Void, Void, String>() { @Override protected String doInBackground(Void... params) { String msg = ""; try { if (gcm == null) { gcm = GoogleCloudMessaging.getInstance(context); } regid = gcm.register(SENDER_ID); msg = "Device registered, registration ID=" + regid; // You should send the registration ID to your server over // HTTP, so it // can use GCM/HTTP or CCS to send messages to your app. sendRegistrationIdToBackend(); // For this demo: we don't need to send it because the // device will send // upstream messages to a server that echo back the message // using the // 'from' address in the message. // Persist the regID - no need to register again. storeRegistrationId(context, regid); } catch (IOException ex) { msg = "Error :" + ex.getMessage(); // If there is an error, don't just keep trying to register. // Require the user to click a button again, or perform // exponential back-off. } return msg; } @Override protected void onPostExecute(String msg) { mDisplay.append(msg + "\n"); } }.execute(null, null, null); } 我收到错误： 03-01 19:15:36.261: E/AndroidRuntime(3467): FATAL EXCEPTION: AsyncTask #1 03-01 19:15:36.261: E/AndroidRuntime(3467): java.lang.RuntimeException: An error occured while executing doInBackground() 03-01 19:15:36.261: E/AndroidRuntime(3467): at android.os.AsyncTask$3.done(AsyncTask.java:299) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.util.concurrent.FutureTask.setException(FutureTask.java:219) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.util.concurrent.FutureTask.run(FutureTask.java:239) 03-01 19:15:36.261: E/AndroidRuntime(3467): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.lang.Thread.run(Thread.java:841) 03-01 19:15:36.261: E/AndroidRuntime(3467): Caused by: java.lang.SecurityException: Not allowed to start service Intent { act=com.google.android.c2dm.intent.REGISTER pkg=com.google.android.gms (has extras) } without permission com.google.android.c2dm.permission.RECEIVE 03-01 19:15:36.261: E/AndroidRuntime(3467): at android.app.ContextImpl.startServiceAsUser(ContextImpl.java:1800) 03-01 19:15:36.261: E/AndroidRuntime(3467): at android.app.ContextImpl.startService(ContextImpl.java:1772) 03-01 19:15:36.261: E/AndroidRuntime(3467): at android.content.ContextWrapper.startService(ContextWrapper.java:480) 03-01 19:15:36.261: E/AndroidRuntime(3467): at com.google.android.gms.gcm.GoogleCloudMessaging.b(Unknown Source) 03-01 19:15:36.261: E/AndroidRuntime(3467): at com.google.android.gms.gcm.GoogleCloudMessaging.register(Unknown Source) 03-01 19:15:36.261: E/AndroidRuntime(3467): at com.example.gcm.DemoActivity$1.doInBackground(DemoActivity.java:177) 03-01 19:15:36.261: E/AndroidRuntime(3467): at com.example.gcm.DemoActivity$1.doInBackground(DemoActivity.java:1) 03-01 19:15:36.261: E/AndroidRuntime(3467): at android.os.AsyncTask$2.call(AsyncTask.java:287) 03-01 19:15:36.261: E/AndroidRuntime(3467): at java.util.concurrent.FutureTask.run(FutureTask.java:234) 03-01 19:15:36.261: E/AndroidRuntime(3467): ... 4 more 这是我的清单： <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.manyexampleapp" android:installLocation="preferExternal" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="11" android:targetSdkVersion="18" /> <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.GET_ACCOUNTS" /> <uses-permission android:name="android.permission.WAKE_LOCK" /> <uses-permission android:name="com.example.manyexampleapp.c2dm.permission.RECEIVE" /> <uses-permission android:name="com.example.manyexampleapp.gcm.permission.C2D_MESSAGE" /> <permission android:name="com.example.manyexampleapp.gcm.permission.C2D_MESSAGE" android:protectionLevel="signature" /> <application android:name="com.zoomer.ifs.BaseApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" /> <activity android:name="com.zoomer.ifs.MainActivity" android:label="@string/app_name" android:configChanges="orientation|keyboardHidden|screenSize" android:launchMode="singleTop">  </activity>   <receiver android:name="com.example.gcm.GcmBroadcastReceiver" android:permission="com.google.android.c2dm.permission.SEND" > <intent-filter>  <action android:name="com.google.android.c2dm.intent.RECEIVE" /> <category android:name="com.example.manyexampleapp" /> </intent-filter> </receiver> <service android:name="com.example.gcm.GcmIntentService" /> <activity android:name="com.example.gcm.DemoActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity>  <activity android:name="com.example.db.DbActivity" android:label="@string/app_name" > <intent-filter> </intent-filter> </activity> <activity android:name="com.example.http.RestGetActivity" android:label="@string/app_name" android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen" > </activity> <activity android:name="com.example.fb.FacebookLoginActivity" android:label="@string/app_name" >  </activity> <activity android:name="com.example.http.SendFeedbackActivity" android:label="@string/app_name" >  </activity> <activity android:name="com.zoomer.general.SearchNearbyOffersActivity" android:label="@string/app_name" > <intent-filter> </intent-filter> </activity> <activity android:name="com.facebook.LoginActivity" android:label="@string/app_name" > <intent-filter> </intent-filter> </activity> <activity android:name="com.example.manyexampleapp.StoresListActivity" > <intent-filter> </intent-filter> </activity> <activity android:name="com.example.fb.ShareActivity" > <intent-filter> </intent-filter> </activity> <activity android:name="com.example.notifications.NotificationsActivity" > <intent-filter> </intent-filter> </activity> <activity android:name="com.example.fb2.no_use.MainActivity" > <intent-filter> </intent-filter> </activity> <activity android:name="com.zoomer.offers.OffersListActivity" >  </activity> <activity android:name="com.example.http.SearchNearbyOffersActivity" >  </activity> <service android:name="com.example.geo.LocationService" android:enabled="true" /> <receiver android:name="com.example.manyexampleapp.BootReceiver" > <intent-filter> <action android:name="android.intent.action.BOOT_COMPLETED" /> <action android:name="com.example.manyexampleapp.LocationService.LOCATION_BROAD_MSG" /> </intent-filter> </receiver> <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id" /> </application> </manifest> 改变 <uses-permission android:name="com.example.manyexampleapp.c2dm.permission.RECEIVE" /> 到  <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" /> 您收到异常是因为您尚未定义所需的权限如果应用程序开发后安装了播放服务，可能会发生 com.google.android.c2dm.permission.RECEIVE 权限已被授予但 android 仍在抱怨同样的错误。在这种情况下，您必须完全重新安装开发的应用程序才能使此权限发挥作用。我认为你必须检查 Kotlin 版本兼容性。

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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