Angular 5 模拟输入控件上的按键

问题描述

我正在尝试在输入控件上按下 Enter 时模拟 Tab 键按下.为此，我使用了一个指令:

I'm trying to simulate tab key press when enter is pressed on input control.For that I use a directive:

 private el: ElementRef;
    @Input() onEnter: string;
    constructor(private _el: ElementRef, public renderer: Renderer) {
        this.el = this._el;
    }
    @HostListener('keydown', ['$event']) onKeyDown(e: any) {
        if ((e.which === 13 || e.keyCode === 13)) {
            e.preventDefault();


    const event = new KeyboardEvent("keypress", {
            "key": "Tab"
          });
          this.el.nativeElement.dispatchEvent(event);
............

回车键代码触发但没有发送标签

code for enter key fires but no tab is sent

推荐答案

更新这个stackblitz(对不起，我不记得我说的那个帖子了)

Updated see better aproach inthis stackblitz(sorry,I don't remember the post where I talk about it)

如果你想使用 ENTER 来聚焦一个元素，你可以使用指令

If you want to use ENTER to focus an element you can use a directive

@Directive({
  selector: '[next-tab]',
})
export class NextTabDirective {


  @Input('next-tab') nextControl: any;

  @HostListener("keydown.enter", ["$event"])
  onEnter(event: KeyboardEvent) {
    if (this.nextControl) {
      if (this.nextControl.focus) {
        this.nextControl.focus();
        this.nextControl.select();
        event.preventDefault();
        return false;
      }
    }
  }

  constructor(private control: NgControl) {
  }
}

你可以像

  <form (submit)="Submit()">
      <input #input0 [next-tab]="input1"  />
      <input #input1 [next-tab]="input2"  />
      <!--the last not have [next-tab]-->
      <!-an ENTER make a submit -->
      <input #input2   />
       <button type="button" (click)="cancel()">Cancel</button>
       <button type="submit">OK</button>
   </form>

我不想使用这种丑陋的解决方法，但我们可以改进指令作为下一个选项卡发送控件数组

I would like not use this ugly work-around, but we can improve the directive sending as next-tab an array of controls

@Directive({
  selector: '[next-tab]',
})
export class NextTabDirective {

  @Input('next-tab') nextControl: any[]; //<--an array of controls

  @HostListener("keydown.enter", ["$event"])
  onEnter(event: KeyboardEvent) {

    //find the nextControl not disabled. We check if c is defined
    //This allow us to use *ngIf and not put the control
    let nextControl=this.nextControl.find(c=>c && !c.disabled);
    if (nextControl) {
      if (nextControl.focus) {
        nextControl.focus();
        nextControl.select();
        event.preventDefault();
        return false;
      }
    }
  }

  constructor(private control: NgControl) {
  }
}

表格看起来像

   <form (submit)="Submit()">
      <!--see that we create an array-->
      <input #input0 [next-tab]="[input1,input2,input3]"  />
      <input #input1 [next-tab]="[input2,input3]"  />
      <!--if only one element, we make an array of one element-->
      <input #input2 [style.display]="existInput2?'inherit':'none'" [next-tab]="[input3]"   />
      <!--if we want make invisible control NOT use *nfIf, therefore, we must hidden and disabled too -->

      <input #input3 />
       <button type="button" (click)="cancel()">Cancel</button>
       <button type="submit">OK</button>
   </form>

最后我在 https://stackblitz.com/edit/angular-v8fkkf

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