downfile.asp

关于设备管理的大型系统

<%
Function downLoadFile(FileSpec)
on error resume next
 Const ForReading=1
 Const TristateTrue=-1 
 Const FILE_TRANSFER_SIZE=1024 '16384
 Dim objFileSystem, objFile, objStream
 Dim char
 Dim sent
 Set objFileSystem = CreateObject("Scripting.FileSystemObject")
 If objFileSystem.FileExists(fileSpec)=false Then
 response.write("<Script>alert(""请求文件不存在！"");history.back();</script>")
 Exit Function
 End If
 FileName = objFileSystem.GetFileName(FileSpec)
 send=0
 TransferFile = True
 Set objFileSystem = Server.CreateObject("Scripting.FileSystemObject")
 Set objFile = objFileSystem.GetFile(FileSpec)
 Set objStream = objFile.OpenAsTextStream(ForReading, TristateTrue)
 Response.AddHeader "content-type", "application/octet-stream"
 Response.AddHeader "Content-Disposition","attachment;filename=" & filename
 
 Response.AddHeader "content-length", objFile.Size
 Do While Not objStream.AtEndOfStream
 char = objStream.Read(1)
 Response.BinaryWrite(char)
 sent = sent + 1
 If (sent MOD FILE_TRANSFER_SIZE) = 0 Then
 Response.Flush
 If Not Response.IsClientConnected Then
 TransferFile = False
 Exit Do
 End If
 End If
 Loop
 Response.Flush
 If Not Response.IsClientConnected Then TransferFile = False
 objStream.Close
 Set objStream = Nothing
 Set objFileSystem = Nothing
End Function
fileSpec =Lcase(Cstr(Trim(Request("fileSpec"))))
 downLoadFile(fileSpec)
%>