Angular 6 中 ngIf 中的多个条件答案

【问题标题】：Multiple Conditions in ngIf in Angular 6Angular 6 中 ngIf 中的多个条件
【发布时间】：2019-01-27 13:47:11
【问题描述】：

我想隐藏一个 div 并想显示另一个我写在下面的代码

我的问题是我在 ngIf 中使用了多个条件但无法正常工作。一旦我点击“显示子内容1”，想要隐藏主要内容并想要显示“子内容1”，反之亦然所有按钮。我应该为此做些什么。请帮忙。

【问题讨论】：

标签： angular typescript angular5 angular6 angular-ng-if

【解决方案1】：

你刚刚接近你的结果，查看你的代码看起来你正在学习，干得好！您必须检查是否启用了任何内容，因此您需要隐藏所有三个按钮并显示您的子内容。以下是根据您的要求的正确代码，

<!-- Display all of the SubContents is disable. -->
<div *ngIf="!showSubContent && !showSubContentTwo && !showSubContentThree">
     <button (click)="showSubContent=!showSubContent">Show Sub content1</button>
     <button (click)="showSubContentTwo=!showSubContentTwo">Show Sub content2</button>
     <button (click)="showSubContentThree=!showSubContentThree">Show Sub content3</button> 
     <h2>  Main content </h2>
</div>

<!-- Display if SubContent-1 is enable. -->
<div *ngIf="showSubContent && !showSubContentTwo && !showSubContentThree">
    Sub Content 1 here
    <button (click)="showSubContent=!showSubContent">Show Main Content</button>
</div>

<!-- Display if SubContent-2 is enable. -->
<div *ngIf="showSubContentTwo && !showSubContent && !showSubContentThree">
    Sub Content 2 here
    <button (click)="showSubContentTwo=!showSubContentTwo">Show Main Content</button>
</div>

<!-- Display if SubContent-3 is enable. -->
<div *ngIf="showSubContentThree && !showSubContentTwo && !showSubContent">
    Sub Content 3 here
    <button (click)="showSubContentThree=!showSubContentThree">Show Main Content</button>
</div>

【讨论】：

非常感谢@Nasiruddin Saiyed :)
代码

【解决方案2】：

您可以使用ngSwitch 简化您的代码：

<div [ngSwitch]="showSubContent">

  <div *ngSwitchDefault>
      <button (click)="showSubContent=1">Show Sub content1</button>
      <button (click)="showSubContent=2">Show Sub content2</button>
      <button (click)="showSubContent=3">Show Sub content3</button> 
      <h2>  Main content </h2>
  </div>

  <div *ngSwitchCase="1">
      Sub Content 1 here
  </div>

   <div *ngSwitchCase="2">
      Sub Content 2 here
  </div>


  <div *ngSwitchCase="3">
      Sub Content 3 here
  </div>

  <button *ngIf="showSubContent" (click)="showSubContent=0">Show Main Content</button>
</div>

【讨论】：

【解决方案3】：

没有必要使用这么多条件来制作这样的作品。这也不是直观的理解你的逻辑，而是使用 switch

// Define a variable with name content in component
export class AppComponent  {
content = 'mainContent'
constructor() {
}}

<div>
   <button (click)="content='showSubContent'">Show Sub content1</button>
   <button (click)="content='showSubContentTwo'">Show Sub content2</button>
   <button (click)="content='showSubContentThree'">Show Sub content3</button>
 </div>
<div [ngSwitch]="content">

 <div *ngSwitchDefault>
   My Main content
  </div> 
<div *ngSwitchCase="'showSubContent'">
   Sub Content 1 here
   <button (click)="content='showMainContent'">Show Main Content</button>
</div>

<div *ngSwitchCase="'showSubContentTwo'">
   Sub Content 2 here
   <button (click)="content='showMainContent'">Show Main Content</button>
</div>

<div *ngSwitchCase="'showSubContentThree'">
   Sub Content 3 here
   <button (click)="content='showMainContent'">Show Main Content</button>
</div>
</div>

【讨论】：