Angular 7：构建于prod：属性'service'是私有的，只能在类“Component”中访问

Question

我正在使用Angular 7.我运行此cmd ng build --prod构建以进行保护。

那个时候我正在缓存这个错误（属性'服务'是私有的，只能在类'LoginComponent'中访问）：

ERROR in src\app\login\login.component.html(5,33): : Property 'service' is private and only accessible within class 'LoginComponent'.
src\app\login\login.component.html(18,104): : Property 'service' is private and only accessible within class 'LoginComponent'.

这是我的HTML代码：

<div id="login_section" class="d-flex justify-content-center align-items-center">
    <div class="login_cnt col-8 row">
        <div class="col-6 d-flex justify-content-center py-4">
            
            <form class="col-8" [formGroup]="service.loginform">
                <h2 class="text-center">User Login</h2>
                <mat-form-field class="col-12">
                  <input matInput type="text" placeholder="Username" formControlName="username" >
                  <mat-error>Username is Required</mat-error>
                </mat-form-field>
              
                <mat-form-field class="col-12">
                  <input matInput [type]="hide ? 'password' : 'text'" formControlName="password" placeholder="Password">
                  <mat-icon matSuffix (click)="hide = !hide">{{hide ? 'visibility_off' : 'visibility'}}</mat-icon>
                  <mat-error>Password is Required</mat-error>
                </mat-form-field>
                <a href="#" class="float-left lnk_forgot h7">Forgot Password</a>
                <button mat-raised-button color="primary" class="float-right" [routerLink]="['/home']" [disabled]="service.loginform.invalid">Login</button>
              </form>
        </div>
    </div>
</div>

这是我的TS文件：

import { Component, OnInit } from '@angular/core';
import { LoginService } from '../shared/login.service';

@Component({
  selector: 'app-login',
  templateUrl: './login.component.html',
  styleUrls: ['./login.component.scss']
})
export class LoginComponent implements OnInit {
  username : string;
  password: string;
  hide = true;

  constructor(private service: LoginService) { }
  ngOnInit() {
  }

}

当运行服务时，我没有抓住它。

Answer 1

有两种方法可以解决这个问题。 1。 将private service: LoginService改为public service: LoginService 在编译期间使用AOT时，无法在HTML模板中访问组件的私有属性。

2.

如果要将服务保密，可以在控制器中提供返回服务属性的公共方法。您可以从HTML模板中调用此方法。它会是这样的：

模板：

<div id="login_section" class="d-flex justify-content-center align-items-center">
    <div class="login_cnt col-8 row">
        <div class="col-6 d-flex justify-content-center py-4">

            <form class="col-8" [formGroup]="getLoginForm()"> <!-- Change here-->
                <h2 class="text-center">User Login</h2>
                <mat-form-field class="col-12">
                  <input matInput type="text" placeholder="Username" formControlName="username" >
                  <mat-error>Username is Required</mat-error>
                </mat-form-field>

                <mat-form-field class="col-12">
                  <input matInput [type]="hide ? 'password' : 'text'" formControlName="password" placeholder="Password">
                  <mat-icon matSuffix (click)="hide = !hide">{{hide ? 'visibility_off' : 'visibility'}}</mat-icon>
                  <mat-error>Password is Required</mat-error>
                </mat-form-field>
                <a href="#" class="float-left lnk_forgot h7">Forgot Password</a>
                <button mat-raised-button color="primary" class="float-right" [routerLink]="['/home']" [disabled]="getLoginForm().invalid">Login</button> <!-- Change here-->
              </form>
        </div>
    </div>
</div>

控制器：

import { Component, OnInit } from '@angular/core';
import { LoginService } from '../shared/login.service';

@Component({
  selector: 'app-login',
  templateUrl: './login.component.html',
  styleUrls: ['./login.component.scss']
})
export class LoginComponent implements OnInit {
  username : string;
  password: string;
  hide = true;

  constructor(private service: LoginService) { }
  ngOnInit() {
  }

  getLoginForm() {
    return this.service.loginform;
  }
}

P.S：我现在还没有亲自测试过第二个。

Answer 2

您需要使访问说明符公开才能使其可访问

constructor(public service: LoginService) { }

Answer 3

似乎您正在使用Ahead-of-Time编译（构建时），并且您正在尝试访问其模板service，[disabled]="service.loginform.invalid"中组件的私有成员（service.loginform）。但是在模板和ahead-of-time compilation中使用它必须是公开的：

constructor(private service: LoginService) { }

应该：

// your component: change private service to public service
constructor(public service: LoginService) { }

// then you can use it like this in the template of your component:
[formGroup]="service.loginform"

[disabled]="service.loginform.invalid"

如果您需要私有服务并且仍需要在组件模板中使用其某些成员，请使用get或其他方法（公共）返回该成员：

// your component
constructor(private service: LoginService) { }

get loginForm() {
  return this.service.loginform;
}

get loginIsInvalid(): boolean {
  return this.service.loginform.invalid;
}

// then in the template of your component you can use:
[formGroup]="loginform"

[disabled]="loginIsInvalid"