angular下H5上传图片，可预览，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