Angular 2 - 在setTimeout中使用'this' [英] Angular 2 - Using 'this' inside setTimeout

问题描述

我的课程中有这样的功能

I have a function like so in my class

  showMessageSuccess(){

    var that = this;
    this.messageSuccess = true;

    setTimeout(function(){
      that.messageSuccess = false;
    },3000);

  }

我如何重写这个，所以我不这样做必须在'that'var中存储'this'的引用？如果我在setTimeout中使用'this'，则messageSuccess bool似乎不会更改/获取更新。

How can I re-write this so I don't have to store a reference to 'this' in the 'that' var? If I use 'this' inside the setTimeout, the messageSuccess bool doesn't seem to change/get updated.

推荐答案

你需要使用ArrowFunction （）=> 在<$ c $中保留 此 上下文C>的setTimeout 。

You need to use ArrowFunction ()=> to preserve this context within setTimeout.

// var that = this; // no need of this line
this.messageSuccess = true;

setTimeout(()=>{    //<<<---    using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

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