通过键盘箭头选择的元素上的Angular 4 fire click事件

Question

目前，我可以通过向上和向下按箭头键来浏览列表中应用css类“message-list-active”的每条消息。当我点击行时，我触发点击功能并传递消息对象。但是当按下箭头键时似乎无法点击该元素，我试图通过#fire单击它，但它只点击第一个元素并赢得'允许我转到下一个列表。

app.html

<div #fire *ngFor="let message of messages; let i=index" 
           (click)="addMessage(message); activeIndex = i"

  [ngClass]="{'message-list-active': activeIndex === i  }">
     {{message}}
  </div>

component.ts

 messages;  // we have date stored here
 activeIndex = 0;

  onAddtoMessage(message) {
    message.active = !message.active;

}

  @ViewChild('fire') fileInput: ElementRef;

  @HostListener("document:keydown", ['$event']) 
  doSomething(event: KeyboardEvent): void {


    if (event.code == "ArrowUp" && this.activeIndex > 0) {
        this.activeIndex--
        this.fileInput.nativeElement.click()
    }
    if (event.code == "ArrowDown" && this.activeIndex < this.messages.length - 1) {
        this.activeIndex++
        this.fileInput.nativeElement.click()
    }
   }

如何使用向上箭头键/向下键来触发所选行（对象）上的单击功能？

Answer 1

好的，所以通过绑定到id来计算它，所以你按id获取元素并应用一个点击，首先设置一个id

<div id="{{i}}" *ngFor="let message of messages; let i=index" 
       (click)="addMessage(message); activeIndex = i"
      [ngClass]="{'message-list-active': activeIndex === i  }">
      {{message}}
 </div>

component.ts

if (event.code == "ArrowUp" && this.activeIndex > 0) {
    this.activeIndex--
     document.getElementById(this.activeIndex.toString()).click();
}
if (event.code == "ArrowDown" && this.activeIndex < this.messages.length - 1) {
    this.activeIndex++
     document.getElementById(this.activeIndex.toString()).click();
  }
}