javascript - Angular Material $mdDialog - 无法访问确认函数中的 'this' 项

Question

我正在尝试使用 Angular Material $mdDialog 的确认功能来清除数组，然后将此数组记录到控制台，但访问“this”对象/数组/表达式/函数似乎存在问题在 $mdDialog 函数本身中，控制台显示任何引用的项目都是未定义的，即使之前在其他 Controller 函数中使用过也是如此。

$mdDialog 指令是否存在 controllerAs 语法问题？

-

Controller :

app.controller('notificationsController', function($scope, $state, $http, $document, $mdDialog, $filter, $timeout) {

this.selectedNotification = null;
this.notifications = [
    {
        title: 'Notification One',
        description: 'Description...',
        time: '2017-10-27T16:39:32+00:00',
        importance: 'Low',
        read: false
    },

    etc...

$scope.clearNotifications = function(ev) {
    var confirm = $mdDialog.confirm()
        .parent(angular.element('body'))
        .clickOutsideToClose(true)
        .title('Are you sure you want to clear all notifications?')
        .textContent('This action cannot be undone.')
        .ariaLabel('Confirm notifications list clearance')
        .ok('Yes')
        .cancel('No')
        .targetEvent(ev)

    $mdDialog.show(confirm).then(function() {
        $scope.status = 'All notifications deleted';
        console.log($scope.status);
        this.notifications.length = 0;
        console.log(this.notifications);
    }, function() {
        $scope.status = 'Notifications list not cleared';
        console.log($scope.status);
    })
}

Answer 1

this 在:

$mdDialog.show(confirm).then(function() {
    ...
    this.notifications.length = 0; // <---- here
    ...
}, function() {
    ...
})

指的是 $mdDialog.show() 返回的 promise 的 promise 解析函数，如果你想访问你必须创建的 Controller 的 notifications 成员引用 Controller 的 this 的 var:

app.controller('notificationsController', function($scope, $state,           
$http, $document, $mdDialog, $filter, $timeout) {

  var _this = this; // <--- Now _this is the controller
  this.notifications = [
  {
    title: 'Notification One',
    description: 'Description...',
    time: '2017-10-27T16:39:32+00:00',
    importance: 'Low',
    read: false
  },

etc...

$scope.clearNotifications = function(ev) {
  ...

  $mdDialog.show(confirm).then(function() {
    ...
    _this.notifications.length = 0; //<--- using _this and not this
    ...
  }, function() {
    ...
  })
}