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AJAX上传(xmlhttp上传文件突破大小限制)

Category:电脑专业 View: Author:zesee

upload.htm

<HTML>
<HEAD><TITLE>File upload</TITLE>
</HEAD>
<BODY>
<form name="upload">
<table width="100%" border="0" cellpadding="5" cellspacing="0">
  <tr>
    <td colspan="2">上传提示：Microsoft ADO/RDS
此页正在访问其他域的数据。您允许这样做吗？</td>
  </tr>
  <tr>
    <td width="100">您的图片</td>
    <td><input name="pic" type="file" size="20"></td>
  </tr>
  <tr>
    <td colspan="2" align="center"><input id="upbtn" type=button value="/blog/上传"></td>
  </tr>
</table>
</form>
<img src="/blog/image.asp" border="0">
</BODY>
</HTML>

<SCRIPT LANGUAGE=JavaScript>
var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");

var st, up
try{
 st = new ActiveXObject("ADODB.Stream");
 up = true
}
catch(e){
 up = false
}
function upload.upbtn.onclick(){
 var uPic = upload.pic.value
 if (validPic()!="") alert(validPic())
 else{
  if(!up) alert("您的浏览器版本太低，无法上传图片，请升级您的浏览器！")
  else{
   st.Type = 1;
   st.Open();
   try{
    st.LoadFromFile(uPic);
    var db = st.Read()
    st.close()
    var txtP = splitString(ByteToStr(db),100000)//这里把已经转换成字符串的文件切割一下，我是按10万字节长度切割的，也就是50KB
    var xmldoc = new ActiveXObject("Microsoft.XMLDOM");
    xmldoc.loadXML('<?xml version="1.0"?><root/>');
    for (var i=0;i<txtP.length;i++){
     var iPic = xmldoc.createElement("pic")
     iPic.text = txtP;
     xmldoc.documentElement.appendChild(iPic);
    }
    xmlhttp.open("POST","upload.asp",true);
    xmlhttp.onreadystatechange = rep
    xmlhttp.send(xmldoc);
   }
   catch(e){alert("无法找到文件！\n"+e.description)}
  }
 }
}

function rep(){
 if(xmlhttp.readyState==4){
  if (xmlhttp.status==200){
   alert(xmlhttp.responseBody)
   location.reload()
  }else
   alert("status:"+xmlhttp.status+"\n"+xmlhttp.statusText)
 }
}

function validPic(){
 var maxSize = 500//最大的尺寸限制
 var str = ''
 var thisPic = new Image();
 thisPic.src = upload.pic.value
 if(thisPic.src=="") str = '请选择您要上传的图片'
 else{
  var picSize = thisPic.fileSize/1024
  if(picSize>maxSize) str = '上传的图片不要大于'+maxSize+'KB，您的图片有'+picSize+'KB'
  else{
   var sPic = thisPic.src.split(".")
   var pf = sPic[sPic.length-1].toLowerCase()
   str = '未知的图片格式!'
   var picF = new Array("gif","jpg","jpeg","bmp")
   for (var i=0;i<picF.length;i++){
    if (pf==picF){
     str = ''
     break
    }
   }
  }
 }
 return str
}

//把二进制文件转换成字符串
function ByteToStr(p){
 var xmldom = new ActiveXObject("Microsoft.XMLDOM");
 xmldom.async = false
 xmldom.loadXML('<?xml version="1.0"?><root/>');
 var tPic = xmldom.createElement("pic")
 tPic.dataType = 'bin.hex'
 tPic.nodeTypedValue = p
 xmldom.documentElement.appendChild(tPic);
 return(String(tPic.text))
}

//把字符串按你想要的长度切割
function splitString(s,l){
 var h = s.length
 var al = (s.length%l==0)?h/l:parseInt(String((s.length/l)).split(".")[0])+1
 var a = new Array(al)
 for (var i=0;i<a.length;i++)
  a = s.substring(i*l,l*(i+1))
 return(a)
}
</SCRIPT>
<img src="/blog/image.asp?id=0" border="0">

upload.asp

<%@ LANGUAGE=VBScript%>
<%Option Explicit%>
<%
Response.ContentType="text/xml"
Response.Charset="UTF-8"
dim xmldom
dim root,pic
set xmldom = Server.CreateObject("Microsoft.XMLDOM")
xmldom.async = false
xmldom.load Request
if xmldom.parseError.errorCode<>0 then
 Response.BinaryWrite "未知的错误！"
else
 if xmldom.readyState=4 then
  xmldom.save Server.MapPath("image.xml")
  Response.BinaryWrite "上传成功！"
  '如果想直接放到数据库，就这么着：
  'dim i,a,txtP,byteP
  'set a = xmldom.documentElement.selectNodes("/root/pic")
  'txtP = ""
  'for i=0 to a.length-1
  'txtP = txtP & a(i).text
  'next
  'byteP = StrToByte(txtP)'这就是你要的东东
 end if
end if
%>
<script language="javascript" runat="server">
function StrToByte(str){
 var xmldom = Server.CreateObject("Microsoft.XMLDOM")
 xmldom.loadXML('<?xml version="1.0"?><root/>')
 var bPic = xmldom.createElement("pic")
 bPic.dataType = "bin.hex"
 bPic.nodeTypedValue = str
 xmldom.documentElement.appendChild(bPic)
 return(bPic.nodeTypedValue)
}
</script>
 

image.asp
 

 <%@language=jscript%>
<%
var xmldoc = new ActiveXObject("Microsoft.XMLDOM")
xmldoc.async = false
xmldoc.load(Server.MapPath("image.xml"))
if (xmldoc.parseError.errorCode!=0){
 Response.Write("error")
}else{
 var a = xmldoc.documentElement.selectNodes("/root/pic")
 var pic = ''
 for (var i=0;i<a.length;i++)
  pic += a.text//这里就是把数据重组
 Response.BinaryWrite(StrToByte(pic))
}

//把字符串转换成二进制流
function StrToByte(str){
 var XMLDOC = Server.CreateObject("Microsoft.XMLDOM")
 XMLDOC.loadXML('<?xml version="1.0"?><root/>')
 var bPic = XMLDOC.createElement("pic")
 bPic.dataType = "bin.hex"
 bPic.nodeTypedValue = str
 XMLDOC.documentElement.appendChild(bPic)
 return(bPic.nodeTypedValue)
}
%>

 

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