服务不会以角度向控制器返回数据

service does not return data to controller in angular

本文关键字:控制器 返回 数据 服务      更新时间:2023-09-26

这是我的服务:

app.service('trackService', ['$http', function($http) {
    var data;
    this.topTracks = function(limit) {
        $http({
            method: 'GET',
            url: 'http://ws.audioscrobbler.com/2.0/?method=chart.gettoptracks',
            params: {api_key: 'e8452c5962aafbb3e87c66e4aaaf5cbf', format: 'json', limit: limit}
        }).success(function(result) {
            this.data = result.tracks; console.log(this.data); return this.data;
        }); 
    }
}]);

和控制器-

app.controller('artistSongsCtrl', ['$scope', 'trackService', function($scope, trackService) {
    $scope.data = trackService.topTracks(10);
    //console.log($scope.data);
}]);

如何在自定义服务中使用$http服务将数据发送到controller?

几个问题是$http是异步的,并且您的服务方法topTracks()不返回任何内容。此外,您不能返回success内部,无处返回。。。使用then()代替

您需要从服务返回promise,并在控制器中的promise回调中设置作用域

app.service('trackService', ['$http',
  function($http) {
    var data;
    var self = this;
    this.topTracks = function(limit) {
      return $http({
        method: 'GET',
        url: 'http://ws.audioscrobbler.com/2.0/?method=chart.gettoptracks',
        params: {
          api_key: 'e8452c5962aafbb3e87c66e4aaaf5cbf',
          format: 'json',
          limit: limit
        }
      }).then(function(result) {
        self.data = result.data.tracks;
        console.log(self.data);
        return self.data;
      });
    }
  }
]);
app.controller('artistSongsCtrl', ['$scope', 'trackService',
  function($scope, trackService) {
    trackService.topTracks(10).then(function(data) {
      $scope.data = data;
      //console.log($scope.data);
    });
  }
]);

在您的服务中,您正在发出异步GET请求。为了让控制器捕获该响应,您需要返回一个promise。下面是一个使用$q:的示例

app.service('trackService', ['$http', '$q', function($http, $q) {
    var data;
    this.topTracks = function(limit) {
        var d = $q.defer();
        $http({
            method: 'GET',
            url: 'http://ws.audioscrobbler.com/2.0/?method=chart.gettoptracks',
            params: {api_key: 'e8452c5962aafbb3e87c66e4aaaf5cbf', format: 'json', limit: limit}
        }).success(function(result) {
            this.data = result.tracks; 
            console.log(this.data); 
            d.resolve(this.data);
        }); 
     return d.promise;
    }
}]);