Angular2 无法在 promise 中访问 'this'

Question

我无法在 ng2-sweetalert2 插件的 promise 中调用函数

swal({
    title: 'Are you sure?',
    text: "You won't be able to revert this!",
    type: 'warning',
    showCancelButton: true,
    confirmButtonText: 'Yes, delete it!'
}).then(function(x) {
    this.removeNote(key);
    swal(
    'Deleted!',
    'Your file has been deleted.',
    'success'
    );
}, function(e){
       console.log('Cancelled');
});

removeNote(key){
    this.todo.remove(key);
    this.afService.closeNote(key);
}

this.removeNote() 导致错误。

EXCEPTION: Uncaught (in promise): TypeError: Cannot read property 'removeNote' of undefined

我该如何克服这个问题？我使用了 NgZone 但我得到了同样的错误

Answer 1

假设您使用的是 TypeScript，您可以使用 arrow function expression ，它保留了 this 的值。

swal({...}).then((x) => console.log(this)); // now 'this' is your component