1、背景
产品提了一个需求，要求在一个html中实现多行多图片上传，原型图如下:
2、实现细节
2.1 ：html
html页面由前端实现，此处增加<ul><li></li></ul>是为了配合图片单击放大图片功能的实现
<ul id="ul_other">
<li><input type="file" id="file_other" class="file_input" onchange="add_file_image('other')"></li>
</ul>
2.2 ：js
var imgSrc_other=[];
var imgFile_other=[];
function add_file_image(id) {
var fileList =document.getElementById("file_"+id).files;// js 获取文件对象
if (verificationFile(fileList[0])){
for(var i =0;i
var imgSrcI =getObjectURL(fileList[i]);
if (id=="other"){
imgSrc_other.push(imgSrcI);
if(fileList[i].size/1024 >100) { //大于100kb，进行压缩上传
fileResizetoFile(fileList[i],0.6,function(res){
imgFile_other.push(res);
})
}else{
imgFile_other.push(res);
}
}
addNewContent(id);
}
}
//新增图片
function addNewContent(obj) {
//删除原先
$("#ul_"+obj).html("");
//判断循环新增
var text="";
if (obj=="other"){
for(var a =0;a < imgSrc_examReportCard.length;a++) {
text +='<li><input type="file" id="file_other" class="file_input" onchange="add_file_image('other')"></li>';
}
}else{
console.log('脏数据');
}
var oldBox ="<li><div class=\"filediv\"><span>+</span>\n" +
"<input type=\"file\" id=\"file_"+obj+"\" class=\"file_input\" onchange=\"add_file_image('"+obj+"')\">\n" +
"</div></li>";
$("#ul_"+obj).html( text+localText);
}
3、上传代码
使用formData上传
var form =document.getElementById("form_addArchive");//表单id
var formData =new FormData(form);
$.each(imgFile_other,function(i, file){
formData.append('imgFileOther', file);
});
$.ajax({
url:url,
type:'POST',
async:true,
cache:false,
contentType:false,
processData:false,
dataType:'json',
data:formData,
xhrFields:{
withCredentials:true
},
success:function(data) {
}
},
error:function(XMLHttpRequest, textStatus, errorThrown) {
}
})
后台使用@RequestParam(value ="imgFileOther", required=false) List<MultipartFile> imgFileOther, 接受
//获取图片url以便显示
function getObjectURL(file) { var url = null ; if (window.createObjectURL!=undefined) { // basic url = window.createObjectURL(file) ; } else if (window.URL!=undefined) { // mozilla(firefox) url = window.URL.createObjectURL(file) ; } else if (window.webkitURL!=undefined) { // webkit or chrome url = window.webkitURL.createObjectURL(file) ; } return url ;}
//文件格式验证
function verificationFile(file) {
var fileTypes = [".jpg", ".png", ".img"];
var isNext = false;var fileEnd = file.name.substring(file.name.indexOf("."));
for (var i = 0; i < fileTypes.length; i++) { if (fileTypes[i] == fileEnd) { isNext = true; break; }}
if (!isNext){ console.log("不接受此文件类型,请选择jpg、png、img图像"); file.value = ""; isNext = false;}return isNext;}
//图片压缩
function urltoImage (url,fn){ var img = new Image(); img.src = url; img.onload = function(){ fn(img); } } function imagetoCanvas(image){ var cvs = document.createElement("canvas"); var ctx = cvs.getContext('2d'); cvs.width = image.width; cvs.height = image.height; ctx.drawImage(image, 0, 0, cvs.width, cvs.height); return cvs ; } function canvasResizetoFile(canvas,quality,fn){ canvas.toBlob(function(blob) { fn(blob); },'image/jpeg',quality); } function filetoDataURL(file,fn){ var reader = new FileReader(); reader.onloadend = function(e){ fn(e.target.result); }; reader.readAsDataURL(file); } function dataURLtoImage(dataurl,fn){ var img = new Image(); img.onload = function() { fn(img); }; img.src = dataurl; } function dataURLtoFile(dataurl) { var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1], bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n); while(n--){ u8arr[n] = bstr.charCodeAt(n); } return new Blob([u8arr], {type:mime}); } function fileResizetoFile(file,quality,fn){ filetoDataURL (file,function(dataurl){ dataURLtoImage(dataurl,function(image){ canvasResizetoFile(imagetoCanvas(image),quality,fn); }) }) }
