javascript – ‘this’在function()中未定义.角度2

参见英文答案 > setTimeout and “this” in JavaScript                                    5个
>            How to access the correct `this` inside a callback?                                    10个
所以我在我的应用程序中使用了uikit confirmation modal.我的问题是,当我要点击< button>确认.这个内部函数是未定义的.这是我的代码……

declare var UIkit:any;

deleteData(dataArr): void {

    UIkit.modal.confirm('Are you sure you want to delete this?', function() {
      console.log(dataArr);
      console.log(this);
      //use service here...
      UIkit.modal.alert('Confirmed!');  
    });
}

在该函数内部我希望使用http请求服务,但我遇到了这个问题.我正在使用Angular 2.x.

解决方法:

使用箭头功能……

declare var UIkit:any;

deleteData(dataArr): void {

  UIkit.modal.confirm('Are you sure you want to delete this?', () => {

    console.log(this);
    // [...]
  });
}

有关此事的详细信息,请查看MDN: Arrow functions.

An arrow function does not create its own this context, so this has
its original meaning from the enclosing context.