Angularjs实现多图片上传预览功能

/**
 * 图片上传获取返回的url
 */
      app .factory('fileReader', ["$q", "$log", function($q, $log){
        var onLoad = function(reader, deferred, scope) {
          return function () {
            scope.$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(); //fileReader
          reader.onload = onLoad(reader, deferred, scope);
          reader.onerror = onError(reader, deferred, scope);
          return reader;
        };

        var readAsDataURL = function (file, scope) {
          var deferred = $q.defer();
          var reader = getReader(deferred, scope);   
          reader.readAsDataURL(file);  
          return deferred.promise;

        };

        return {
          readAsDataUrl: readAsDataURL 
      };
}])

/**
 * 图片上传预览
 */
app .directive('file', ['$parse', 'fileReader', function ($parse, fileReader) { 
      return {
        restrict: 'A',
        link: function(scope, element, attrs, ngModel) {

          var model = $parse(attrs.file);
          var modelSetter = model.assign;
          console.log(modelSetter)
          element.bind('change', function(event){
            scope.$apply(function(){
              modelSetter(scope, element[0].files[0]);
            });
            //附件预览         
               scope.imgupload = (event.srcElement || event.target).files[0];
               getFile(scope.imgupload, scope);

              //获得预览图地址并且把file对象放入上传合集内
               function getFile (imgupload, scope) {
                 if(!imgupload) {
                   return;
                 }
                 fileReader.readAsDataUrl(imgupload, scope)
                        .then(function(result) {
                         scope.imgshows.push(result)
                         var file = document.querySelector('input[type=file]').files[0];
                         scope.uploadimgs.push(file)//这里是放着传给后台的数据file，下面controller的时候会有
                        });
               };
          });
        }
      };
    }]) 

app .directive('uploadimg', function () { 
      return {
        restrict: 'E', 
        scope: {
          uploadimgs: "="
        },
        templateUrl: './js/directives/uploadimg/uploadimg.html',      
        link: function(scope, element, attrs) {
            scope.imgshows = []//预览图片合集放的是src    
            scope.uploadimg_del = function(index,imgs) {  
                scope.imgshows.splice(index,1);
                scope.uploadimgs.splice(index,1);
      }
     }
 }
}) 

<style type="text/css">
.fileupload {
  width: 100px;
  height: 100px;
  border: 1px dotted #ccc;
  display: inline-block;
}
.fileupload-icon {
  font-size:32px;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
}
</style>
<div>
  <div class="fileupload pos-rlt" ng-repeat="imageSrc in imgshows">
    <img ng-src="{{imageSrc}}" style="max-width:200px;max-height:300px;margin:0 auto; display:block;" class="pos-rlt" width=100%; height=100%;/>
    <i class="icon ion-close-circled" style="position: absolute; top:5px; right: 5px" ng-click="uploadimg_del($index, imgshows)"></i>
  </div>
  <div class="fileupload pos-rlt clear" >
    <i class="icon ion-plus-round fileupload-icon"></i>
    <input type="file" style="display:inline-block; width: 100%; height: 100%; opacity:0" name="upload_img" file="upload_img" placeholder="选择图片" accept="image/png,image/gif,image/jpeg,image/jpg"  >
  </div>
</div>
</label>

<uploadimg uploadimgs="uploadimgs"></uploadimg>

$scope.uploadimgs = []//上传图片合集放的是file对象

$scope.save = function() {     
    var Fromdata = {
      'name': $scope.form.name,
      'desc': $scope.form.descr,
      'price': $scope.form.price,
      'status': $scope.form.status?1:0,

    }
    var uploadData = createFromData(Fromdata)
    for(var i = 0; i < $scope.uploadimgs.length; i++) {
      uploadData.append('upload_imgs', $scope.uploadimgs[i])
    }

     $http({
     method:'POST',
     url:"后台地址",
     data: fd,
     headers: {'Content-Type':undefined},
     transformRequest: angular.identity
     })
     .success( function(response){
     //上传成功的操作

     });

   }  

//构造FormData
//@param 是一个对象
function createFromData(Fromdata) {
   var fd = new FormData();
   for(key in Fromdata) {
     fd.append(key,Fromdata[key]); 
   }
   return fd
}