js实现上传单个文件

js上传文件:js 上传单个文件(任意大小)
疯狂代码 http://www.CrazyCoder.cn/ :http:/www.CrazyCoder.cn/Javascript/Article8329.html

var xml_http,ado_stream;
var SendBlockCount,SendCount;
varl astSendTime,maxFileLimit;
var breaked=false;
var _filename;
var blockSize=1024*128;
var isUploaded=false;

maxFileLimit=1024*1024*50;//上传文件的大小

///处理文件开始上传
function BeginSend()
{
try
{
if(document.getElementById("UpFileControl")&&document.getElementById("UpFileControl").value
.length>0)
{
document.getElementById("speed").innerHTML="0KB/Sec";//进度条
document.getElementById("perent").innerHTML="0%";
document.getElementById("perentBar").style.width="0%";
document.getElementById("bar").style.display="block";
//document.getElementById("control").style.display="block";
document.getElementById("divImportData").style.display="block";
_filename=document.getElementById("UpFileControl").value;
document.getElementById("filename").innerHTML="正在上传文件
:"+_filename.substring(_filename.lastIndexOf("\\")+1,_filename.length);

SendFile();
}
elseif(document.getElementById("UpFileControl").value=="")
{
alert("请先选择要上传的文件");
window.parent.AllowFunc(); [Page]
document.getElementById("btnReset").disabled=false;
document.getElementById("btnUpload").disabled=false;
document.getElementById("UpFileControl").disabled=false;
Initialize();
return false;
}
else
{
return false;
}
}
catch(ex)
{
alert("上传文件过程中出错,原因:"+ex.description);
//window.parent.AllowFunc();
document.getElementById("btnReset").disabled=false;
document.getElementById("btnUpload").disabled=false;
document.getElementById("UpFileControl").disabled=false;
Initialize();
return false;
}
}

///开始上传文件
function SendFile()
{
breaked=false;
try
{
ado_stream=newActiveXObject("ADODB.Stream");
ado_stream.Type=1;
ado_stream.Open();
}
catch(ex)
{
window.parent.AllowFunc();