相关疑难解决方法(0)

正如下面提供的代码.我试图选择由ngIf生成的动态元素但是失败了.

我总共用了两种方法.

1. ElementRef和querySelector

组件模板:

    `<div class="test" *ngIf="expr">
      <a id="button">Value 1</a>
    </div>
    <div class="test" *ngIf="!expr">
      <a id="button">Value 2</a>
    </div>`

组件类:

    expr: boolean;

    constructor(
      private elementRef: ElementRef,
    ) {
    }

    ngOnInit(): void{
    //Call Ajax and set the value of this.expr based on the callback;
    //if expr == true, then show text Value 1; 
    //if expr == false, then show text Value 2;
    }
    ngAfterViewInit(): void{
      console.log(this.elementRef.nativeElement.querySelector('#button'));
    }

输出结果是null.

2. @ViewChild

组件模板:

    `<div class="test" *ngIf="expr">
      <a #button>Value 1</a>
    </div>
    <div class="test" *ngIf="!expr"> …