怎么限制上传文件格式

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在源代码里面该嘛

给你一段你照抄

UpFile.asp文件

<!--#include file="conn.asp"-->
<%
'这里是接受COOKice
username=session("username")
passwd=session("Passwd")
%>
<%
' 整个网站的安全要紧啊!如果没登陆那就给我到Login.asp页面去吧!
Set rs = Server.CreateObject("ADODB.Recordset")
sql="select * from admin where username='"&username&"'and passwd='"&passwd&"'"
rs.open sql,conn,1,1
if rs.eof then
response.redirect "login.asp"
response.end
end if
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language="javascript">
function mysubmit(theform)

if(theform.Text_Files.value=="")

alert("请点击浏览按钮，选择您要上传的jpg或gif文件!")
return (false);

else

str= theform.Text_Files.value;
strs=str.toLowerCase();
lens=strs.length;
extname=strs.substring(lens-4,lens);
if(extname!=".jpg" && extname!=".gif")

alert("请选择jpg或gif文件!");
return (false);


return (true);

</script>
</head>

<body>
<table width="293" border="0" cellspacing="0">
<tr>
<td> <form name="FileForm" method="post" enctype="multipart/form-data" action="Save_UpFiles.asp" onsubmit="return mysubmit(this)">
<input name="Text_Files" type="file" style="width:80%">
<input type="submit" name="Submit" value="上传">
</form></td>
</tr>
</table>
</body>
</html>

Save_UpFiles.asp文件

<%
Option Explicit
Response.Buffer = True
Server.ScriptTimeOut = 9999999
%>
<!--#include file="Class_UpFiles.asp" -->
<%
'限制从外部非法提交
If Instr(Request.ServerVariables("http_referer"),"http://" & Request.Servervariables("host") ) < 1 Then
Response.Write "处理 URL 时服务器上出错!请与管理员联系..."
Response.End
End If

Const G_FS_FSO = "Scripting.FileSystemObject" 'FSO组件名称
'---------------------------------------------
Dim AllowFileType
AllowFileType = "jpg|gif"
Dim AllowFileSize
AllowFileSize = 10240
Dim Create_DateCatalog
Create_DateCatalog = True '是否开启创建日期目录
'---------------------------------------------
Dim AutoReName,UpFileObj,FileObject,FormName,FileName,FileExtStr,strFileName
Dim Fso,SavePath,AutoSavePath,AppearErr,ClueOn_Msg,StrJs
Dim SameFileTF,No_UpFileTF,RealityPath
'---------------------------------------------
SavePath = "/" '保存文件目录
If Right(SavePath,1) <> "/" Then
SavePath = SavePath & "/"
End If

Set UpFileObj = New UpFile_Class
UpFileObj.GetData(10240000)

AutoReName = Trim(UpFileObj.Form("AutoRename")) '是否自动重命名文件
ClueOn_Msg = ""
No_UpFileTF = True
AppearErr = False
If IsObjInstalled(G_FS_FSO) = True Then
'------------------------------------------------------------------------------
Set Fso = Server.CreateObject(G_FS_FSO)
'--------------------------------------------------------------------------
For Each FormName in UpFileObj.File '列出所有上传了的文件

Set FileObject = UpFileObj.File(FormName) '生成一个文件对象
SameFileTF = False
FileName = FileObject.FileName
If NoIiiegalStr(FileName) = False Then
ClueOn_Msg = "文件：上传被禁止!"
AppearErr = True
End If

FileExtStr = FileObject.FileExt

If FileObject.FileSize > 1 Then '如果有文件上传
'----------------------------------------------------------------------
If Fso.FolderExists(Server.MapPath(SavePath)) = True Then '检测目录是否存在
If Create_DateCatalog = True Then '如果开启了自动创建日期目录
AutoSavePath = Year(Now()) & Right("0" & Month(Now()),2) & "/"
SavePath = SavePath & AutoSavePath

If Not Fso.FolderExists(Server.MapPath(SavePath)) Then '如不存在目录则建立
Fso.CreateFolder Server.MapPath(SavePath)
End If
End If
Else
ClueOn_Msg = "目录不存在,无法上传文件!"
AppearErr = True
End If
RealityPath = Server.MapPath(SavePath) & "\" '转换虚拟路径为实际路径
'----------------------------------------------------------------------
No_UpFileTF = False
If FileObject.FileSize > Clng(AllowFileSize)*1024 Then
ClueOn_Msg = FileName & "文件超过了限制!\n\n最大只能上传" & AllowFileSize & "K的文件"
AppearErr = True
End If

If AutoRename = "2" Then '如果不是自动从命名文件
If Fso.FileExists(RealityPath & FileName) = True Then
ClueOn_Msg = "文件:存在同名文件"
AppearErr = True
Else
SameFileTF = False
End If
Else
SameFileTF = True
End If

If CheckFileType(AllowFileType,FileExtStr) = False Then '如果文件后缀名不合格
ClueOn_Msg = "此文件不允许上传!\n\n允许上传文件类型有"& AllowFileType &""
AppearErr = True
End If

StrJs = "<script language=javascript>" & vbcrlf
If AppearErr <> True Then
If SameFileTF = True Then
strFileName = DateStr & rndStr(5) & "." & DealExtName(FileExtStr)
Else
strFileName = ReplaceExt(FileName,"shit")
End If

FileObject.SaveToFile Server.MapPath(SavePath & strFileName) '保存文件
' ClueOn_Msg = "文件上传成功!"& SavePath & strFileName &"" '上传成功信息
StrJs = StrJs & "document.write ('<font size=2>[sayyes]"& SavePath & strFileName &"[/sayyes]');" & vbcrlf '上传成功后显示文件所在
StrJs = StrJs & "document.write ('<a href=javascript:history.go(-1)>[继续上传]</a></font>');" & vbcrlf '上传成功后继续上传
End If
' StrJs = StrJs & "alert('" & ClueOn_Msg & "');" & vbcrlf
' StrJs = StrJs & "history.go(-1);" & vbcrlf
StrJs = StrJs & "</script>"
Response.Write strJS
Response.End
Else
Response.Write( "请选择你要上传的文件！")
Response.End
End If
Next
Set FileObject = Nothing
Set Fso = Nothing
Else
Response.Write "上传功能需要FSO组件支持,请检查该组件是否安装正确!"
Response.End
End If
Set UpFileObj = Nothing

'//验证上传文件的合法性
Function CheckFileType(AllowExtStr,FileExtName)
Dim i,AllowArray,LenTmp
LenTmp = Len(FileExtName)
AllowArray = Split(AllowExtStr,"|")
FileExtName = DealExtName(Trim(LCase(FileExtName)))
CheckFileType = False
For i = LBound(AllowArray) to UBound(AllowArray)
If LCase(AllowArray(i)) = LCase(FileExtName) Then
CheckFileType = True
End If
Next
If FileExtName = "asp" or FileExtName = "asa" or FileExtName = "aspx" or FileExtName = "cer" or FileExtName = "php" or FileExtName = "cdx" or FileExtName = "htr" or FileExtName = "exe" Then
CheckFileType = False
Else
If LenTmp <> Len(FileExtName) Then
CheckFileType = False
End If
End If
End Function

'//检查文件名格式
Function NoIiiegalStr(Byval FileNameStr)
Dim Str_Len,Str_Pos
Str_Len = Len(FileNameStr)
Str_Pos = InStr(FileNameStr,Chr(0))
If Str_Pos = 0 or Str_Pos = Str_Len then
NoIiiegalStr = True
Else
NoIiiegalStr = False
End If
End function

'//替换掉禁止的文件类型
Function DealExtName(Byval UpFileExt)
If IsEmpty(UpFileExt) Then Exit Function
DealExtName = Lcase(UpFileExt)
DealExtName = Replace(DealExtName,Chr(0),"")
DealExtName = Replace(DealExtName," ","")
DealExtName = Replace(DealExtName," ","")
DealExtName = Replace(DealExtName,Chr(255),"")
DealExtName = Replace(DealExtName,".","")
DealExtName = Replace(DealExtName,"'","")
DealExtName = Replace(DealExtName,"asp","")
DealExtName = Replace(DealExtName,"asa","")
DealExtName = Replace(DealExtName,"aspx","")
DealExtName = Replace(DealExtName,"cer","")
DealExtName = Replace(DealExtName,"cdx","")
DealExtName = Replace(DealExtName,"htr","")
DealExtName = Replace(DealExtName,"php","")
DealExtName = Replace(DealExtName,"exe","")
End Function

'//如果不开启自动命名,则执行替换
'//替换非法文件为自定义字符串
Function ReplaceExt(Byval ExtStr,Byval RepExt)
If IsEmpty(ExtStr) or IsEmpty(RepExt) Then Exit Function
ReplaceExt = Lcase(ExtStr)
ReplaceExt = Replace(ReplaceExt,Chr(0),"")
ReplaceExt = Replace(ReplaceExt," ","")
ReplaceExt = Replace(ReplaceExt," ","")
ReplaceExt = Replace(ReplaceExt,Chr(255),"")
ReplaceExt = Replace(ReplaceExt,"'","")
ReplaceExt = Replace(Replace(ReplaceExt,"asp",RepExt),".asp","sp" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"asa",RepExt),".asa","sa" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"aspx",RepExt),".aspx","spx" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"cer",RepExt),".cer","er" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"cdx",RepExt),".cdx","dx" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"htr",RepExt),".htr","tr" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"php",RepExt),".php","hp" & RepExt)
ReplaceExt = Replace(Replace(ReplaceExt,"exe",RepExt),".exe","xe" & RepExt)
End Function

'//产生一个日期字符串
Function DateStr()
Dim iYear,iMonth,iDay,iHour,iMinute,iScond
iYear = Year(Now)
iMonth = Month(Now)
iDay = Day(Now)
iHour = CStr(Hour(Now()))
If Len(iHour) = 1 Then
iHour = "0" & iHour
End If

iMinute = CStr(Minute(Now()))
If Len(iMinute) = 1 Then
iMinute = "0" & iMinute
End If

iScond = CStr(Second(Now()))
If Len(iScond) = 1 Then
iScond = "0" & iScond
End If
DateStr = iYear & iMonth & iDay & iHour & iMinute & iScond
End Function

'//生成指定位数的字符
Function rndStr(strLong)
Dim tempStr
Randomize
Do while Len(rndStr) < strLong
tempStr = CStr(Chr((57-48)*rnd+48))
rndStr = rndStr & tempStr
Loop
rndStr = rndStr
End Function

'//检查组件是否安装
Function IsObjInstalled(ByVal strClassString)
Dim xTestObj,ClsString
On Error Resume Next
IsObjInstalled = False
ClsString = strClassString
Err = 0
Set xTestObj = Server.CreateObject(ClsString)
If Err = 0 Then IsObjInstalled = True
If Err = -2147352567 Then IsObjInstalled = True
Set xTestObj = Nothing
Err = 0
Exit Function
End Function
%>

当然照搬是肯定是不能正常使用的

需要按照你的网站具体修改!!

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或加我 QQ:284610811 参考技术A long飞机回答的很好，完成能用

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