无组件文件上传代码案例

关于无组件文件上传的文章已经很多了，所以在这里我不想再解释无组件文件上传的原理。在ASP中无法将二进制文件数据直接保存成文件，所以我们一般还是利用数据库来保存用户上传的文件。

1。数据库表结构(Access)：
UserID:Text(保存上传文件的用户ID)
FileContentType:Text(用来保存上传文件的类型，eg:"Application/msword"，主要用来使用户能正确下载此文件）
FileContent:OLE Object（保存文件数据）

2。HTML文件
muploadfile.htm
<Form name="upload_file" enctype="multipart/form-data" action="muploadfile.asp" method=post>
<input type=hidden name="UserID" value="abc">
<input type=hidden name="FileUploadStart"> '这里用来表示开始文件数据上传
File to send: <BR>
<INPUT TYPE="file" name="file_up" size="30"><br>
<INPUT TYPE="file" name="file_up" size="30"><br>
<input type=hidden name="FileUploadEnd"> '这里用来表示文件数据结束
<input type=submit value=Submit>
</Form>

3。ASP文件
muploadfile.asp

<%
Response.Expires=0
Function bin2str(binstr)
    Dim varlen,clow,ccc,skipflag

    skipflag=0
    ccc = ""
    If Not IsNull(binstr) Then
        varlen=LenB(binstr)
        For i=1 To varlen
            If skipflag=0 Then
                clow = MidB(binstr,i,1)
                If AscB(clow) > 127 Then
                    ccc =ccc & Chr(AscW(MidB(binstr,i+1,1) & clow))
                    skipflag=1
                Else
                    ccc = ccc & Chr(AscB(clow))
                End If
            Else
                skipflag=0
            End If
        Next
    End If
    bin2str = ccc
End Function


varByteCount = Request.TotalBytes
bnCRLF = chrB( 13 ) & chrB( 10 )
binHTTPHeader=Request.BinaryRead(varByteCount)        
Divider = LEFTB( binHTTPHeader,  INSTRB( binHTTPHeader, bnCRLF ) - 1 )

'开始读非文件域的数据
Do while lenB(binHTTPHeader)>46
    
    binHeaderData = LeftB(binHTTPHeader, INSTRB( binHTTPHeader, bnCRLF & bnCRLF )-1)
    strHeaderData=bin2str(binHeaderData)

    lngFieldNameStart=Instr(strHeaderData,"name="&chr(34))+Len("name="&chr(34))
    lngFieldNameEnd=Instr(lngFieldNameStart,strHeaderData,chr(34))
    
    
    strFieldName=Mid(strHeaderData,lngFieldNameStart,lngFieldNameEnd-lngFieldNameStart)
    strFieldName=Trim(strFieldName)
    strFieldName=Replace(strFieldName,vbcrlf,vbnullstring)
    
        '判断文件数据时候开始
    If strComp(strFieldName,"FileUploadStart",1)=0 Then
        binHTTPHeader=MIDB(binHTTPHeader,INSTRB( DataStart + 1, binHTTPHeader, divider ))
        exit do
    End if
    
    DataStart = INSTRB( binHTTPHeader, bnCRLF & bnCRLF ) + 4
    DataEnd = INSTRB( DataStart + 1, binHTTPHeader, divider ) - DataStart

    binFieldValue=MIDB( binHTTPHeader, DataStart, DataEnd )
    strFieldValue=bin2str(binFieldValue)
    strFieldValue=Trim(strFieldValue)
    strFieldValue=Replace(strFieldValue,vbcrlf,vbnullstring)

    '非文件上传域变量赋值
    execute strFieldName&"="""&strFieldValue&""""
    
        
    binHTTPHeader=MIDB(binHTTPHeader,INSTRB( DataStart + 1, binHTTPHeader, divider ))
        
loop

'开始处理文件数据
Do while lenB(binHTTPHeader)>46
    
    
    binHeaderData = LeftB(binHTTPHeader, INSTRB( binHTTPHeader, bnCRLF & bnCRLF )-1)
        
    strHeaderData=bin2str(binHeaderData)
    
    '读取上传文件的Content-Type
    lngFileContentTypeStart=Instr(strHeaderData,"Content-Type:")+Len("Content-Type:")
    strFileContentType=Trim(Mid(strHeaderData,lngFileContentTypeStart))
    strFileContentType=Replace(strFileContentType,vbCRLF,vbNullString)
    
    '读取上传的文件名
    lngFileNameStart=Instr(strHeaderData,"filename="&chr(34))+Len("filename="&chr(34))
    lngFileNameEnd=Instr(lngFileNameStart,strHeaderData,chr(34))
    strFileName=Mid(strHeaderData,lngFileNameStart,lngFileNameEnd-lngFileNameStart)
    strFileName=Trim(strFileName)
    strFileName=Replace(strFileName,vbCRLF,vbNullString)
    
    '读取上传文件数据
    DataStart = INSTRB( binHTTPHeader, bnCRLF & bnCRLF ) + 4
    DataEnd = INSTRB( DataStart + 1, binHTTPHeader, divider ) - DataStart
    
    If strFileName<>"" Then
                
        binFieldValue=MIDB( binHTTPHeader, DataStart, DataEnd )
        
        '将上传的文件写入数据库
        set conn = Server.CreateObject("ADODB.Connection")
        conn.Open "DSN=abc"
        
        SQL="select * from User_File"
        set rs=server.CreateObject("ADODB.Recordset")
        rs.Open sql,conn,3,3
        rs.addnew
        rs("UserID")=UserID
        rs("FileContentType")=strFileContentType
        rs("FileContent").AppendChunk binFieldValue
        rs.update
        rs.close
        set rs=Nothing
        conn.Close
        set conn=Nothing
        
    End if
    
    binHTTPHeader=MIDB(binHTTPHeader,INSTRB( DataStart + 1, binHTTPHeader, divider ))
    
loop
%>

4。下载用户上传的文件
<%
Response.Buffer      = true
Response.Clear

UserID=request("UserID")

Set conn=server.createobject("adodb.connection")
set rs=server.createobject("adodb.recordset")
conn.open "DSN=UploadFile"
rs.open "select * from User_File where UserID='"&UserID&"'",conn,3,3
Response.ContentType = rs("FileContentType")

lngOffset=0
conChunkSize=1024
lngPictSize=rs("FileContent").ActualSize
Do While lngOffset < lngPictSize
  varChunk = rs("FileContent").GetChunk(conChunkSize)
  Response.BinaryWrite varChunk
  lngOffset = lngOffset + conChunkSize
  If lngOffset > lngPictSize Then Exit Do
Loop

rs.close
set rs=Nothing
conn.close
set conn=nothing
%>

就是这些了，希望此方法对大家能有所帮助。：）

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