javascript - 更新 .then 内的 $scope 吗？

Question

我在 Controller 中有一个函数，但我对如何从 .t​​hen 函数内部更新 $scope 变量感到困惑。

这是我的功能:

searchSpotify(query, $scope) {
    this.Spotify.search(query,'track').then(function (data) {
        console.log(data.tracks.items); // this is working
        $scope.result = data;
  }); 
}

在控制台日志中我收到此错误:

TypeError: Cannot set property 'result' of undefined

我是否以某种方式使用$scope.$apply？

编辑:

这是上下文的整个 Controller

(function() {

    class SelectionController {
        constructor(User, groupService, selectionService, songService, $scope, $routeParams, Spotify) {
            this.groupId = $routeParams.groupId;
            this.selectionId = $routeParams.selectionId;
            this.groupService = groupService;
            this.selectionService = selectionService
                //this.selections = this.selectionService.getSelections();
            this.songService = songService;
            this.searchResults;
            this.$scope = $scope;
            this.Spotify = Spotify
        }

        searchSpotify(query) {
            this.Spotify.search(query, 'track').then(function(data) {
                console.log(data.tracks.items);
                $scope.result = data;
            });
        }

        addSong(name, artist, album) {
            alert('called from selection controller');
            this.songService.addSong(this.selectionId, name, artist, album);
        }

        createSelection(name, description) {
            this.selectionService.createSelection(this.groupId, name, description);
        }

        deleteSelection(selection) {
            this.selectionService.deleteSelection(selection);
        }
    }

    angular.module('songSelectionApp')
        .controller('SelectionController', SelectionController);

})();

Answer 1

保存对$scope的引用:

    searchSpotify(query) {
        var $scope = this.$scope;
        this.Spotify.search(query, 'track').then(function(data) {
            console.log(data.tracks.items);
            $scope.result = data;
        });
    }

或者使用arrow functions :

    searchSpotify(query) {
        this.Spotify.search(query, 'track').then((data) => {
            console.log(data.tracks.items);
            this.$scope.result = data;
        });
    }

.bind(this) 也应该有效，正如另一个答案所建议的那样。

关于$scope.$apply:只有当您想要更改$digest之外的$scope时才需要它，例如例如，当您使用外部(非 Angular )库/函数时，例如 WebSocket 或 jquery 事件监听器。直到 Spotify 成为一个 Angular 服务/工厂 - 你不需要 $scope.$apply

来自docs :

$apply() is used to execute an expression in angular from outside of the angular framework. (For example from browser DOM events, setTimeout, XHR or third party libraries).