整体逻辑：service提供FileReader函数，directive提供点击事件的绑定和监听，controller用来修改html上的ng-src属性值

1.HTML

<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*/

2.AngularJS

1)Controller

  .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;});};});

2）Directive

 .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();});}};});

3)Service

 .service('fileReader', function ($q) {// AngularJS will instantiate a singleton by calling "new" on this functionvar onLoad=function (reader,deferred,scope) {return function () {scope.$apply(function () {deferred.resolve(reader.result);});};};var onError=function (reader,deferred,scope) {return function () {scope.$apply(function () {deferred.reject(reader.result);});};};var getReader=function (deferred,scope) {var reader=new FileReader();reader.οnlοad=onLoad(reader,deferred,scope);reader.οnerrοr=onError(reader,deferred,scope);return reader;}var readAsDataURL=function (file,scope) {/*上传图片的主函数*/var deferred=$q.defer();var reader=getReader(deferred,scope);reader.readAsDataURL(file);return deferred.promise;};return{readAsDataUrl:readAsDataURL};});