<input type="file" file-model="myFile">/*AngularJS定义的file-Model属性用于对文件进行操作*/

<img alt="配图预览" ng-src="{{imageSrc}}">/*这里用来放置上传的图片进行预览，ng-src是AngularJS定义替代<img>标签的src属性，其值将在后台逻辑获得*/

  .controller('AddarticleCtrl', function ($scope,fileReader) {/*Controller是实际操作html元素的部分*/

    $scope.getFile= function () {

      fileReader.readAsDataUrl($scope.myFile,$scope)/*注意这里$scope.myFile，要看实际情况，调试发现这里用该调用入参数的myFile属性*/

        .then(function (result) {

          $scope.imageSrc=result;

        });

      };

  });

 .directive('fileModel', function ($parse) {/*$parse是AngularJS的内置directive*/

    return {

      restrict: 'A',/*限制该directive的声明方式 为Attribute*/

      link: function (scope, element, attrs) {

        var model=$parse(attrs.fileModel);

        var modelSetter=model.assign;

        element.bind('change',function (event) {/*页面加载时执行*/

          scope.$apply(function () {/*当用户点击html上的input标签，选中需要上传的图片 然后点击确定后执行*/

            modelSetter(scope,element[0].files[0]);

          });

          scope.getFile();

        });

      }

    };

  });

 .service('fileReader', function ($q) {

    // AngularJS will instantiate a singleton by calling "new" on this function

    var onLoad=function (reader,deferred,scope) {

      return function () {

        scope.$apply(function () {

          deferred.resolve(reader.result);

        });

      };

    };

    var onError=function (reader,deferred,scope) {

      return function () {

        scope.$apply(function () {

          deferred.reject(reader.result);

        });

      };

    };

    var getReader=function (deferred,scope) {

      var reader=new FileReader();

      reader.onload=onLoad(reader,deferred,scope);

      reader.onerror=onError(reader,deferred,scope);

      return reader;

    }

    var readAsDataURL=function (file,scope) {/*上传图片的主函数*/

      var deferred=$q.defer();

      var reader=getReader(deferred,scope);

      reader.readAsDataURL(file);

      return deferred.promise;

    };

    return{

      readAsDataUrl:readAsDataURL

    };

  });