有时候需要显示进度，这时候就需要做一些切割，具体上传代码如下：
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title></title>
<script src="http://cdn.bootcss.com/jquery/2.2.4/jquery.js"></script>
</head>
<body>
<input type="file" name="my_big_file" id="my_big_file" />
<input type="button" value="上传" id="upload_btn" />
<div id="tip"></div> <script type="text/javascript">
$(function(){
//页面加载完毕后开始执行的事件
$("#upload_btn").click(function(){
if($("#my_big_file").val()=="")
{
console.log("请选择文件");return false;
}
var file= document.getElementById("my_big_file").files[0];
var total_size=file.size;
var step=1024*1024;
var num=Math.ceil(total_size/step);
var has_loaded=0;
for(var i=0;i<num;i++)
{
has_loaded+=step;
//var reader= new FileReader();
//reader.readAsBinaryString(file.slice(has_loaded,has_loaded+step));
$("#tip").html("当前进度 "+has_loaded/total_size*100+"%");
sleep(10);
console.log("当前进度 "+has_loaded/total_size*100+"%");
//reader.onprogress=function(e){
//console.log(this.result);
//console.log("当前进度 "+has_loaded/total_size*100+"%");
//};
}
});
});
function sleep(numberMillis) {
var now = new Date();
var exitTime = now.getTime() + numberMillis;
while (true)
{
now = new Date();
if (now.getTime() > exitTime)
{
return;
}
}
}
</script>
</body>
</html>