Angular:从另一个指令获取主机上一个指令实例的引用

Question

我的模板:

<div myDirective myOtherDirective>Hello World</div>

我的指令:

@Directive({
    selector: '[myDirective]',
})
export class MyDirective {
  private readonly otherDirective: MyOtherDirective; // How to instantiate this?
}

我如何获得对 myOtherDirective 的引用从内部 MyDirective ?

Answer 1

它应该可以通过 DI 获得

@Directive({
    selector: '[myDirective]',
})
export class MyDirective {
  constructor(private otherDirective: MyOtherDirective) {}
}

如果同一个元素上没有这样的指令，那么请确保您使用 @Optional装饰者。

或者，您可以将其作为 @Input 传递

my-other.directive.ts

@Directive({
    selector: '[myOtherDirective]',
    exportAs: 'myOtherDirective'
})
export class MyOtherDirective {}

模板.html

<div myDirective [otherDirective]="other" #other="myOtherDirective" 
      myOtherDirective>Hello World</div>

my.directive.ts

@Directive({
   selector: '[myDirective]',
})
export class MyDirective {
   @Input() otherDirective: MyOtherDirective;
}