使用ng模型变量的角度2中的ng变化 [英] using the ng change in angular 2 using ng model variable

问题描述

如何在角度2中使用ng-change事件?每当ng-model变量更改时，都必须调用一个函数.

How can I use the ng-change event in angular 2? Whenever the ng-model variable is changed, a function has to be called.

[(ngModel)]="variable"
ngchange=variable;

推荐答案

您可以使用ngModelChange事件:

[(ngModel)]="variable" (ngModelChange)="doSomething($event)"

修改

根据您的评论，我认为您应该使用带有自定义验证程序的表单控件.

According to your comment, I think that you should use form control with a custom validator.

以下是示例:

@Component({
  (...)
  template: `
    <input [(ngModel)]="variable" [ngFormControl]="ctrl"/>
  `
})
export class SomeComponent {
  constructor() {
    this.ctrl = new Control('', (control) => {
      // validate the value
    });

    this.ctrl.valueChanges.subscribe((value) => {
      // called when the value is updated
    });

  }
}

有关更多详细信息，请参见本文:

See this article for more details:

• http://restlet.com/blog/2016/02/11/implementing-angular2-forms-beyond-basics-part-1/

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