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
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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
});
});
});
};
}])
= 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.$apply(function() {
var img = new Image();
//前端压缩图片
img.onload = function(){
//resize the image using canvas
var canvas = document.createElement("canvas");
var ctx = canvas.getContext("2d");
var width = img.width;
var height = img.height;
var MAX_WIDTH = width>2500 ? width/2 : 2500;
var MAX_HEIGHT = height>2500 ? height/2 : 2500;
if (width > height) {
if (width > MAX_WIDTH) {
height *= MAX_WIDTH / width;
width = MAX_WIDTH;
}
} else {
if (height > MAX_HEIGHT) {
width *= MAX_HEIGHT / height;
height = MAX_HEIGHT;
}
}
canvas.width = width ;
canvas.height = height;
ctx.drawImage(img,width,height);
var dataURL = canvas.toDataURL('image/jpeg',1);
var blob = dataURItoBlob(dataURL);
if(blob.size > 2000 * 1024){
dataURL = canvas.toDataURL('image/jpeg',.2);
}else if(blob.size > 1000 * 1024){
dataURL = canvas.toDataURL('image/jpeg',.5);
}else{
dataURL = canvas.toDataURL('image/jpeg',.8);
}
blob = dataURItoBlob(dataURL);
deferred.resolve(blob);
}
img.src = URL.createObjectURL(file);
});
};
};
var onError = function(reader,scope) {
return function() {
scope.$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,file) {
var reader = new FileReader();
reader.onload = onLoad(reader,file);
reader.onerror = onError(reader,scope);
reader.onprogress = onProgress(reader,scope);
return reader;
};
var readAsDataURL = function(file,scope) {
var deferred = $q.defer();
var reader = getReader(deferred,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(),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
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//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)
}
});
});
$rootScope.showAttachment = false;
};return false;
}
这里处理了下图片,在名字上加了序号,因为在ios上每次选择的图片名字都叫image,查找了很多资料,说是safari的bug,后面版本才会解决,暂时只能以这种方式解决了。循环是上传多张图片
3.HTML代码
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- x
{{formData.attachvo[$index].attachmentType}}
4.顺便把formdata时代码贴一下,采用H5上传图片的方式
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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
以上所述是小编给大家介绍的Angular下H5上传图片的方法(可多张上传)。编程之家 jb51.cc 收集整理的教程希望能对你有所帮助,如果觉得编程之家不错,可分享给好友!感谢支持。