ngClass的ExpressionChangedAfterItHasBeenCheckedError [英] ExpressionChangedAfterItHasBeenCheckedError with ngClass

问题描述

我有两个锚标签

 <ul class="switchNav">
          <li [ngClass]="!hidePanel2 ? 'active' : ''">
            <a href="javascript:void(0)" (click) ="hideShowPanel(1)">panel 1</a>
          </li>
          <li [ngClass]="!hidePanel1? 'active' : ''">
            <a href="javascript:void(0)" (click) ="hideShowPanel(2)">panel 2</a>
          </li>
        </ul>

.ts

hidePanel2: boolean  = true;
 hidePanel1: boolean  = false;

 hideShowPanel(check: number) {
    if (check == 1) {
      this.hidePanel2 = true;
      this.hidePanel1 = false;
    }
    else {
      this.hidePanel1 = false;
      this.hidePanel2 = true;
    }

  }

当我点击锚标记时，它会引发错误

When I click on anchor tag it throws an error

ExpressionChangedAfterItHaHasBeenCheckedError

ExpressionChangedAfterItHasBeenCheckedError

它正在工作，但是由于团队成员更新了任何模块，所以它停止了工作，

It was working,but due to update any module by a team member it stopped working,

我在Google上搜索了很多，但无法正常运行

I have googled a lot but could not get it working

请帮助

谢谢

推荐答案

要添加到Ritesh的答案中，在这种情况下，您可以做两件事:

To add to Ritesh's answer, in this case you can do two things :

• 在 setTimeout()回调中包装导致此消息的代码
• 告诉Angular进行另一个这样的检测循环:

• wrap the code that causes this message in a setTimeout() callback
• Tell Angular to make another detection loops like this :

-

 constructor(private changeDetector: ChangeDetectorRef) {
 }

 hideShowPanel(check: number) {
 
    if (check == 1) {
        this.hidePanel2 = true;
        this.hidePanel1 = false;
    }
    else {
        this.hidePanel1 = false;
        this.hidePanel2 = true;
    }
    this.changeDetector.detectChanges();
}

我还想提出一篇有趣的文章，解释在幕后发生的事情:您需要了解的所有关于ExpressionChangedAfterItHasBeenCheckedError的信息

I would also like to suggest an interesting article that explains what happens under the hood : Everything you need to know about ExpressionChangedAfterItHasBeenCheckedError

这篇关于ngClass的ExpressionChangedAfterItHasBeenCheckedError的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！