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[Java教程]angular下H5上传图片(可多张上传)

最近做的项目中用到了angular下上传图片功能,在做的过程中遇到了许多问题,最终都得以解决

angular上传时和普通上传时过程差不多,只不过是要不一些东西转化为angular的东西。

1.ng-file-select,指令angular是没此功能的,其实也是转化成了change事件,不多说,直接上代码

angular.module('myApp')
.directive('ngFileSelect', [ '$parse', '$timeout', function($parse, $timeout) { return function(scope, elem, attr) { var fn = $parse(attr['ngFileSelect']); elem.bind('change', function(evt) { var files = [], fileList, i; fileList = evt.target.files; if (fileList != null) { for (i = 0; i < fileList.length; i++) { files.push(fileList.item(i)); } } $timeout(function() { fn(scope, { $files : files, $event : evt }); }); }); }; }])

2.服务 上传文件前预览并压缩图片功能

//上传文件预览angular.module('myServers',[])  .factory('fileReader', ['$q', '$log', function($q, $log) {    var dataURItoBlob = function(dataURI) {       // convert base64/URLEncoded data component to raw binary data held in a string       var byteString;       if (dataURI.split(',')[0].indexOf('base64') >= 0)         byteString = atob(dataURI.split(',')[1]);       else         byteString = unescape(dataURI.split(',')[1]);          // separate out the mime component       var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];          // write the bytes of the string to a typed array       var ia = new Uint8Array(byteString.length);       for (var i = 0; i < byteString.length; i++) {         ia[i] = byteString.charCodeAt(i);       }          return new Blob([ia], {         type: mimeString       });     };              var onLoad = function(reader, deferred, scope,file) {      return function() {        scope.$apply(function() {           var img = new Image();          //前端压缩图片          img.onload = function(){             //resize the image using canvas             var canvas = document.createElement("canvas");             var ctx = canvas.getContext("2d");             var width = img.width;             var height = img.height;                         var MAX_WIDTH = width>2500 ? width/2 : 2500;             var MAX_HEIGHT = height>2500 ? height/2 : 2500;            if (width > height) {               if (width > MAX_WIDTH) {                 height *= MAX_WIDTH / width;                 width = MAX_WIDTH;               }             } else {               if (height > MAX_HEIGHT) {                 width *= MAX_HEIGHT / height;                 height = MAX_HEIGHT;               }             }              canvas.width = width ;             canvas.height = height;               ctx.drawImage(img, 0, 0, width, height);                           var dataURL = canvas.toDataURL('image/jpeg', 1);            var blob = dataURItoBlob(dataURL);             if(blob.size > 2000 * 1024){              dataURL = canvas.toDataURL('image/jpeg', .2);            }else if(blob.size > 1000 * 1024){              dataURL = canvas.toDataURL('image/jpeg', .5);                          }else{              dataURL = canvas.toDataURL('image/jpeg', .8);            }            blob = dataURItoBlob(dataURL);            deferred.resolve(blob);          }          img.src = URL.createObjectURL(file);                  });      };    };    var onError = function(reader, deferred, scope) {      return function() {        scope.$apply(function() {          deferred.reject(reader.result);        });      };    };    var onProgress = function(reader, scope) {      return function(event) {                scope.$broadcast("fileProgress", {          total: event.total,          loaded: event.loaded        });      };    };    var getReader = function(deferred, scope, file) {      var reader = new FileReader();      reader.onload = onLoad(reader, deferred, scope,file);      reader.onerror = onError(reader, deferred, scope);      reader.onprogress = onProgress(reader, scope);      return reader;    };    var readAsDataURL = function(file, scope) {      var deferred = $q.defer();      var reader = getReader(deferred, scope,file);      reader.readAsDataURL(file);      return deferred.promise;    };    return {      readAsDataUrl: readAsDataURL    };  }]);

这里说明一下,部分代码是参考别人的代码(http://blog.csdn.net/zx007fack/article/details/41073601),但是对其中内容做了修改,因为用原来的代码,如果不加前端压缩功能是正常的,前端压缩的话因为要用到canvas, 直接用reader.result在ios上图片的宽高拿到的直接是0,android上是可以的,具体原因不是很确定是不是base64的问题,所以我又直接把file传了进来,然后用原生js的方法新建图片元素拿到宽高,再用Canvas进行压缩,最后转成blob,通过formData传给后台。

3.controller代码

//选择图片后执行的方法    $scope.fileArr = [];    $scope.imgSrcArr = [];var i = 0; //为ios上图片都为image时添加序号    $rootScope.onFileSelect = function(files, event) {      //预览上传图片开始      $rootScope.startLoading();      var $this = angular.element(event.target);      angular.forEach(files, function(value, index) {        var fileIn = value;        var fileInName = fileIn.name;        var fileType = fileInName.substring(fileInName.lastIndexOf(".") + 1, fileInName.length);        //解决ios下所有图片都为image.jpg的bug        if(fileIn) {          fileInName = fileInName.split('.')[0] + i + '.' + fileType;          i++;        }                attachvo.push({          name: fileInName,          type: fileType        });                 fileReader.readAsDataUrl(fileIn, $scope)          .then(function(result) {            result.name = fileInName;            $scope.fileArr.push(result);            $scope.imgSrcArr.push(URL.createObjectURL(result));
              //每次上传后清空file框,确保每次都能调用change事件 document.querySelector('.upload').reset(); }); $scope.$on('fileProgress', function(event, data) { if(data.total == data.loaded) { $timeout(function() { //上传图片结束 $rootScope.endLoading(); }, 200) } }); }); $rootScope.showAttachment = false; };return false; }

这里处理了下图片,在名字上加了序号,因为在ios上每次选择的图片名字都叫image,查找了很多资料,说是safari的bug,后面版本才会解决,暂时只能以这种方式解决了。循环是上传多张图片

3.html代码

<ul class="upload-view-ul">        <li ng-repeat="src in imgSrcArr" class="pull-left" ng-click="delCurUpload(src)"       ng-class="{'row-last': (($index+1) % 5==0)}">      <span>x</span>      <em ng-if='nrc'>{{formData.attachvo[$index].attachmentType}}</em>      <img ng-src="{{src}}">    </li>    <div class="attachment" pop-type-select ng-if="nrc">+</div>        <div class="attachment" ng-if="!nrc">      +      <form class="upload">        <input type="file" name="file[]" ng-file-select="onFileSelect($files, $event)" multiple>      </form>    </div>  </ul>

4.顺便把formdata时代码贴一下,采用H5上传图片的方式

this.FormdataPost = function(pathUrl, formId, formData, files) {    var fd = new FormData();    fd.append('formId', formId);    if(files && angular.isArray(files)) {      files.forEach(function(item) {        fd.append('file', item, item.name);      });    }    fd.append('formData', angular.toJson(formData, true));    var httpConfig = {      headers: {        'Authorization': 'Bearer ' + this.token,        'Content-Type': undefined      },      transformRequest: angular.identity    };    return $http.post(rootUrl + pathUrl, fd, httpConfig).then(function(data) {      return data;    }).catch(function(error) {      $rootScope.interfaceName = pathUrl;      $rootScope.setNewWortStatus({        status: error.status,        errInfo: error.data && error.data.statusInfo || ''      });      return error;    });  }

思路有一点混乱,不知道讲清楚了没有,想起来再添加吧