JavaScript实现多张图片上传功能

时间:2024-07-25 15:07:32

今天闲着没事,把之前的多张图片上传代码整理了下。

页面主要代码:

 <div class="upBox upBox2">
<div class="d1">
<a class="redA1 rightA" href="javascript:choosePhotos();" id="continue_add_button" style="display:none;">继续添加</a>
</div>
<div class="d2" id="add_photo_button">
<a href="javascript:choosePhotos();" class="blueA1">从电脑上传照片</a>
<p class="p1">注:支持JPG格式多张上传,按住Ctrl或Shift选择图片,一次最多可上传150张照片</p>
</div>
<input type="file" id="upload" accept="image/jpeg" multiple="multiple" style="display:none;" />
<canvas id="myCanvas" style="display:none;"></canvas>
<div class="d3">
<ul class="ul1 clearfix" id="local_upload_div"> </ul>
</div>
</div>

js部分主要代码,其实不用html5的画布也行,不过貌似用画布页面加载比直接预览图较快。

具体上传代码没写,和单张上传是一样的,需要的朋友可以去我的另一篇写单张上传的博客里看一下:JavaScript实现单张图片上传功能

 //准备上传的模板
var mb_upload = "<li id=\"up_li_INDEX\">"+
"<div>"+
"<div class=\"imgD\">" +
"<img id=\"up_img_INDEX\" src=\"/img/upload/morenI.png\" >"+
"</div>" +
"<p class=\"jdP\" id=\"up_p_INDEX\">" +
"<img class=\"i1\" src=\"/img/upload/loading.gif\">"+
"准备上传"+
"</p>" +
"</div>"+
"</li>"; $(function(){
//文件域改变时触发
$('#upload').change(function (evt) {
fileChange(evt);
});
}); //触发文件域
function choosePhotos(){
$("#upload").click();
} //文件域改变时触发
function fileChange(evt){
var files = evt.target.files;
if(files.length == 0)return;
//上传页面已有照片数量
var up_page_num = $("#local_upload_div li").length; $("#add_photo_button").hide();
$("#continue_add_button").show(); layer.msg('照片加载中', {icon: 16}); for(var m=0; m<files.length; m++){
var f = files[m];
console.log("type="+f.type+" name="+f.name+" length="+f.size);
addPhoto(m+1+up_page_num);
}
getImagesInfo(files,0,up_page_num); } //页面添加等待上传的预显示图片
function addPhoto(i){
var segment = mb_upload;
segment = segment.replace(/INDEX/g,i);
$("#local_upload_div").append(segment);
} //获取到照片信息并在页面添加预览图
var getImagesInfo = function(files,a,up_page_num){ if(files.length > a){ usUploading = true; var f = files[a]; ///var type = f.type;
//获取容器
var c = document.getElementById("myCanvas");
//获取画布对象
var cxt = c.getContext("2d"); var reader = new FileReader(); var name = f.name;//完整照片名称,带格式 //异步方法,文件读取完毕才执行
reader.onload = function(e){
//图片的读取结果
var dataImg = e.target.result;
var img = new Image();
//异步方法
img.onload = function(){
var ratio = img.width/img.height;
var h,w;
//等比例压缩宽和高
if(ratio>1){
w = 110;
h = w*img.height/img.width;
}else{
h = 110;
w = h*img.width/img.height;
}
//容器设置宽和高
c.width = w;
c.height = h;
//清空容器
cxt.clearRect(0, 0, w, h);
//开始作画
cxt.drawImage(img,0,0,w,h);
//获取容器中画的url
var compressed = c.toDataURL("image/jpeg"); //将预览图插入上传页面
$("#up_img_"+(a+1+up_page_num)).attr("src",compressed);
$("#up_img_"+(a+1+up_page_num)).show("slow"); syncUpload(files,dataImg,a,name,up_page_num);
};
//将图片的读取结果赋到img对象的src属性上
img.src = dataImg;
};
//将图片读取为URL数据:base64编码
reader.readAsDataURL(f);
}
} //原图上传
var syncUpload = function(files,imgStr,index,name,up_page_num){ sleep(1000);//延时1s,模拟ajax,O(∩_∩)O哈哈~ //这里就是和单张上传逻辑一样了,只不过在上传成功后再次调用上面的方法,具体上传的方法就不写了
$("#up_p_"+(index+1+up_page_num)).html("<img class=\"i1\" src=\"/img/upload/duihao2.png\">"+
"上传成功"+
"<a href=\"javascript:void(0);\" class=\"right\"><img class=\"i2\" src=\"/img/upload/shanI.gif\"></a>"); getImagesInfo(files,++index,up_page_num); }; //设置延时函数
function sleep(numberMillis) {
var now = new Date();
var exitTime = now.getTime() + numberMillis;
while (true) {
now = new Date();
if (now.getTime() > exitTime)return;
}
}

看看基本效果O(∩_∩)O:

JavaScript实现多张图片上传功能