跳过程序中的值更改Angular 2控件的更改 [英] Skip programmatic changes in valueChanges of Angular 2 control

问题描述

我正在订阅Angular 2(2.2.1)控件的valueChanges.它是在AbstractControl的@angular \ forms \ src \ model.d.ts中定义的，并且它的文档字符串指出它将可以从UI以及程序化的UI中进行更改:

I'm subscribing to the valueChanges observable of an Angular 2 (2.2.1) control. It's defined in AbstractControl in @angular\forms\src\model.d.ts and it's doc string states that it will yiald changes from the UI as well as programmatic ones:

/**
 * Emits an event every time the value of the control changes, in
 * the UI or programmatically.
 */
valueChanges: Observable<any>;

我该如何过滤掉它，只给我UI上的更改，而不能给我编程上的更改?

我认为布尔型道具(原始，肮脏，被触摸等)对我没有帮助，因为即使在控件被标记为肮脏之后-表示我想捕获的UI更改-可能是进一步的程序更改，我想忽略.

I think that the boolean props (pristine, dirty, touched, etc.) won't help me, because even after a control is marked dirty - indicating a change from the UI, which I would like to capture - there might be further programmatic changes, which I would like to ignore.

推荐答案

您可以使用

control.setValue(123, {emitEvent: false})

另请参见

• https://angular.io/docs/ts/latest/api/forms/index/AbstractControl-class.html#!#setValue-anchor
• https://github .com/angular/angular/blob/e9f307f9488e44879dc027e5f4436fb6bc046fa4/modules/％40angular/forms/src/model.ts#L669

• https://angular.io/docs/ts/latest/api/forms/index/AbstractControl-class.html#!#setValue-anchor
• https://github.com/angular/angular/blob/e9f307f9488e44879dc027e5f4436fb6bc046fa4/modules/%40angular/forms/src/model.ts#L669

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