然而有些情况只需要传递几个文件，而且文件体积并不太大，这种情况下使用组件则有点牛刀杀鸡的感觉，通过html自带的<input type="file">表单就可以实现需要的功能，关键在于后台接收程序的处理。

php处理上传做的很方便，上传文件的信息通过服务器自动处理到$_FILES数组中，开发者只需要使用的内置处理函数简单操作就可以啦。ASP开发者则没有这么幸运，官方并没有提供直接的处理方法，需要开发者自己设计，这时就需要开发者了解IIS对enctype="multipart/form-data"表单的处理方式，IIS把enctype="multipart/form-data"表单提交的数据存储成二进制数据，以二进制格式返回给开发者，开发者则需要通过LenB、MidB的字节处理函数来分析获取的上传内容，客户端发送的具体表单数据格式，可以了解下HTTP RFC1867协议传输格式方面的知识。

下面是我处理多个文件上传的方法，包括php和asp两个版本。

php：WEBSITE_DIRROOT代表网站根目录：
复制代码 代码如下:
<?php
/*
* class: 文件上传类
* author: 51JS.COM-ZMM
* date: 2011.1.20
* email: 304924248@qq.com
* blog: http://www.cnblogs.com/cnzmm/
*/

class Upload {
public $up_ext=array(), $up_max=5210, $up_dir;
private $up_name, $up_rename=true, $up_num=0, $up_files=array(), $up_ret=array();

function __construct($name, $ext=array(), $rename=true) {
if (!empty($name)) {
$this->up_name = $name;
!empty($ext) && $this->up_ext = $ext;
$this->up_rename = $rename;
$this->up_dir = WEBSITE_DIRROOT.
$GLOBALS['cfg_upload_path'];
$this->InitUpload();
} else {
exit('upload文件域名称为空，初始化失败！');
}
}

private function InitUpload() {
if (is_array($_FILES[$this->up_name])) {
$up_arr = count($_FILES[$this->up_name]);
$up_all = count($_FILES[$this->up_name], 1);
$up_cnt = ($up_all - $up_arr) / $up_arr;
for ($i = 0; $i < $up_cnt; $i ++) {
if ($_FILES[$this->up_name]['error'][$i] != 4) {
$this->up_files[] = array(
'tmp_name' => $_FILES[$this->up_name]['tmp_name'][$i],
'name' => $_FILES[$this->up_name]['name'][$i],
'type' => $_FILES[$this->up_name]['type'][$i],
'size' => $_FILES[$this->up_name]['size'][$i],
'error' => $_FILES[$this->up_name]['error'][$i]
);
}
}
$this->up_num = count($this->up_files);
} else {
if (isset($_FILES[$this->up_name])) {
$this->up_files = array(
'tmp_name' => $_FILES[$this->up_name]['tmp_name'],
'name' => $_FILES[$this->up_name]['name'],
'type' => $_FILES[$this->up_name]['type'],
'size' => $_FILES[$this->up_name]['size'],
'error' => $_FILES[$this->up_name]['error']
);
$this->up_num = 1;
} else {
exit('没找找到需要upload的文件！');
}
}

$this->ChkUpload();
}

private function ChkUpload() {
if (empty($this->up_ext)) {
$up_mime = array('image/wbmp', 'image/bmp', 'image/gif', 'image/pjpeg', 'image/x-png');
foreach ($this->up_files as $up_file) {
$up_allw = false;
foreach ($up_mime as $mime) {
if ($up_file['type'] == $mime) {
$up_allw = true; break;
}
}
!$up_allw && exit('不允许上传'.$up_file['type'].'格式的文件！');

if ($up_file['size'] / 1024 > $this->up_max) {
exit('不允许上传大于 '.$this->up_max.'K 的文件！');
}
}
} else {
foreach ($this->up_files as $up_file) {
$up_ext = end(explode('.', $up_file['name']));

$up_allw = false;
foreach ($this->up_ext as $ext) {
if ($up_ext == $ext) {
$up_allw = true; break;
}
}
!$up_allw && exit('不允许上传.'.$up_ext.'格式的文件！');

if ($up_file['size'] / 1024 > $this->up_max) {
exit('不允许上传大于 '.$this->up_max.'K 的文件！');
}
}
}

$this->Uploading();
}

private function Uploading() {
if (IO::DIRCreate($this->up_dir)) {
if (chmod($this->up_dir, 0777)) {
if (!empty($this->up_files)) {
foreach ($this->up_files as $up_file) {
if (is_uploaded_file($up_file['tmp_name'])) {
$file_name = $up_file['name'];
if ($this->up_rename) {
$file_ext = end(explode('.', $file_name));
$file_rnd = substr(md5(uniqid()), mt_rand(0, 26), 6);
$file_name = date('ymdHis').'_'.$file_rnd.'.'.$file_ext;
}
$file_name = $this->up_dir.'/'.$file_name;

if (move_uploaded_file($up_file['tmp_name'], $file_name)) {
$this->up_ret[] = str_replace(WEBSITE_DIRROOT, '', $file_name);
} else {
exit('文件上传失败！');
}
}
}
}
} else {
exit('未开启写入权限！');
}
} else {
exit('上传目录创建失败！');
}
}

public function GetUpload() {
return empty($this->up_ret) ? false : $this->up_ret;
}

function __destruct() {}
}
?>


asp：
复制代码 代码如下:
<%
Class MultiUpload

REM PUBLIC-VARIANT

Public Form, IsFinished
Private bVbCrlf, bSeparate, fPassed, formData, fileType, fileSize, folderPath, _
fRename, fIMGOnly, itemCount, chunkSize, bTime, sErrors, sAuthor, sVersion
Private itemStart(), itemLength(), dataStart(), dataLength(), itemName(), itemData(), extenArr(), httpArr()

REM CLASS-INITIALIZE

Private Sub Class_Initialize
Call InitVariant
Server.ScriptTimeOut = 1800
Set Form = Server.CreateObject("Scripting.Dictionary")
sAuthor = "51JS.COM-ZMM"
sVersion = "MultiUpload Class 3.0"
End Sub

REM CLASS-ATTRIBUTES

Public Property Let AllowType(byVal sType)
Dim regEx
Set regEx = New RegExp
regEx.Pattern = "^(\w+\|)*\w+$"
regEx.Global = False
regEx.IgnoreCase = True
If regEx.Test(sType) Then fileType = "|" & Ucase(sType) & "|"
Set regEx = Nothing
End Property

Public Property Let MaxSize(byVal sSize)
If IsNumeric(sSize) Then fileSize = CDbl(FormatNumber(CCur(sSize), 2))
End Property

Public Property Let SaveFolder(byVal sFolder)
folderPath = sFolder
End Property

Public Property Let CommonPassed(byVal bCheck)
fPassed = bCheck
End Property

Public Property Let FileRenamed(byVal bRename)
fRename = bRename
End Property

Public Property Let FileIsAllImg(byVal bOnly)
fIMGOnly = bOnly
End Property

Public Property Get SaveFolder
SaveFolder = folderPath
End Property

Public Property Get FileRenamed
FileRenamed = fRename
End Property

Public Property Get FileIsAllImg
FileIsAllImg = fIMGOnly
End Property

Public Property Get ErrMessage
ErrMessage = sErrors
End Property

Public Property Get ClsAuthor
ClsAuthor = sAuthor
End Property

Public Property Get ClsVersion
ClsVersion = sVersion
End Property

REM CLASS-METHODS

Private Function InitVariant
IsFinished = False
bVbCrlf = StrToByte(vbCrlf & vbCrlf)
bSeparate = StrToByte(String(29, "-"))
fPassed = False
fileType = "*"
fileSize = "*"
fRename = True
fIMGOnly = True
itemCount = 0
chunkSize = 1024 * 128
bTime = Now
sErrors = ""
End Function

Public Function GetUploadData
Dim curRead : curRead = 0
Dim dataLen : dataLen = Request.TotalBytes
Dim appName : appName = "PROGRESS" & IPToNum(GetClientIPAddr)
Dim streamTmp
Set streamTmp = Server.CreateObject("ADODB.Stream")
streamTmp.Type = 1
streamTmp.Open
Do While curRead < dataLen
Dim partLen : partLen = chunkSize
If partLen + curRead > dataLen Then partLen = dataLen - curRead
streamTmp.Write Request.BinaryRead(partLen)
curRead = curRead + partLen
LetProgress appName, Array(curRead, dataLen, DateDiff("s", bTime, Now), folderPath)
Loop
streamTmp.Position = 0
formData = streamTmp.Read(dataLen)
streamTmp.Close
Set streamTmp = Nothing
Call ItemPosition
End Function

Private Function LetProgress(byVal sName, byVal vArr)
Application.Value(sName) = Join(vArr, "|")
End Function

Private Function DelProgress
Application.Contents.Remove("PROGRESS" & IPToNum(GetClientIPAddr))
End Function

Private Function ItemPosition
Dim iStart, iLength : iStart = 1
Do Until InStrB(iStart, formData, bSeparate) = 0
iStart = InStrB(iStart, formData, bSeparate) + LenB(bSeparate) + 14
iLength = InStrB(iStart, formData, bSeparate) - iStart - 2
If Abs(iStart + 2 - LenB(formData)) > 2 Then
ReDim Preserve itemStart(itemCount)
ReDim Preserve itemLength(itemCount)
itemStart(itemCount) = iStart
itemLength(itemCount) = iLength
itemCount = itemCount + 1
End If
Loop
Call FillItemValue
End Function

Private Function FillItemValue
Dim dataPart, bInfor
Dim iStart : iStart = 1
Dim iCount : iCount = 0
Dim iCheck : iCheck = StrToByte("filename")
For i = 0 To itemCount - 1
ReDim Preserve itemName(iCount)
ReDim Preserve itemData(iCount)
ReDim Preserve extenArr(iCount)
ReDim Preserve httpArr(iCount)
ReDim Preserve dataStart(iCount)
ReDim Preserve dataLength(iCount)
dataPart = MidB(formData, itemStart(i), itemLength(i))
iStart = InStrB(1, dataPart, ChrB(34)) + 1
iLength = InStrB(iStart, dataPart, ChrB(34)) - iStart
itemName(iCount) = GetItemName(MidB(dataPart, iStart, iLength))
iStart = InStrB(1, dataPart, bVBCrlf) + 4
iLength = LenB(dataPart) - iStart + 1
If InStrB(1, dataPart, iCheck) > 0 Then
bInfor = MidB(dataPart, 1, iStart - 5)
extenArr(iCount) = FileExtenName(bInfor)
httpArr(iCount) = GetHttpContent(bInfor)
If IsNothing(extenArr(iCount)) Then
itemData(iCount) = ""
dataStart(iCount) = ""
dataLength(iCount) = ""
Else
If Mid(folderPath, Len(folderPath) - 1) = "/" Then
If fRename Then
itemData(iCount) = folderPath & GetRandomName(6) & extenArr(iCount)
Else
itemData(iCount) = folderPath & GetClientName(bInfor) & extenArr(iCount)
End If
Else
If fRename Then
itemData(iCount) = folderPath & "/" & GetRandomName(6) & extenArr(iCount)
Else
itemData(iCount) = folderPath & "/" & GetClientName(bInfor) & extenArr(iCount)
End If
End If
dataStart(iCount) = itemStart(i) + iStart - 2
dataLength(iCount) = iLength
End If
Else
extenArr(iCount) = ""
httpArr(iCount) = ""
itemData(iCount) = ByteToStr(MidB(dataPart, iStart, iLength))
dataStart(iCount) = ""
dataLength(iCount) = ""
End If
iCount = iCount + 1
Next
Call ItemToColl
End Function

Private Function GetItemName(byVal bName)
GetItemName = ByteToStr(bName)
End Function

Private Function ItemToColl
For i = 0 To itemCount - 1
If Not Form.Exists(itemName(i)) Then
Form.Add itemName(i), itemData(i)
End If
Next
End Function

Private Function FileExtenName(byVal bInfor)
Dim pContent, regEx
pContent = GetClientPath(bInfor)
If IsNothing(pContent) Then
FileExtenName = ""
Else
Set regEx = New RegExp
regEx.Pattern = "^.+(\.[^\.]+)$"
regEx.Global = False
regEx.IgnoreCase = True
FileExtenName = regEx.Replace(pContent, "$1")
Set regEx = Nothing
End If
End Function

Private Function GetHttpContent(byVal bInfor)
Dim sInfor, regEx
sInfor = ByteToStr(bInfor)
Set regEx = New RegExp
regEx.Pattern = "^[\S\s]+Content-Type:([\S\s]+)$"
regEx.Global = False
regEx.IgnoreCase = True
GetHttpContent = Trim(regEx.Replace(sInfor, "$1"))
Set regEx = Nothing
End Function

Private Function GetRandomName(byVal sLen)
Dim regEx, sTemp, arrFields, n : n = 0
Set regEx = New RegExp
regEx.Pattern = "[^\d]+"
regEx.Global = True
regEx.IgnoreCase = True
sTemp = regEx.Replace(Now, "") & "-"
Set regEx = Nothing
arrFields = Array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", _
"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", _
"k", "l", "m", "n", "o", "p", "q", "r", "s", "t", _
"u", "v", "w", "x", "y", "z", "A", "B", "C", "D", _
"E", "F", "G", "H", "I", "J", "K", "L", "M", "N", _
"O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", _
"Y", "Z")
Randomize
Do While n < sLen
sTemp = sTemp & CStr(arrFields(61 * Rnd))
n = n + 1
Loop
GetRandomName = sTemp
End Function

Private Function GetClientName(byVal bInfor)
Dim pContent, regEx
pContent = GetClientPath(bInfor)
If IsNothing(pContent) Then
GetClientName = ""
Else
Set regEx = New RegExp
regEx.Pattern = "^.*\\([^\.]*)[^\\]+$"
regEx.Global = False
regEx.IgnoreCase = True
GetClientName = regEx.Replace(pContent, "$1")
Set regEx = Nothing
End If
End Function

Private Function GetClientPath(byVal bInfor)
Dim sInfor, pStart, pLength, pContent
sInfor = ByteToStr(bInfor)
pStart = InStr(1, sInfor, "filename=" & Chr(34)) + 10
pLength = InStr(pStart, sInfor, Chr(34)) - pStart
pContent = Mid(sInfor, pStart, pLength)
GetClientPath = pContent
End Function

Public Function SaveUploadFile
Dim isValidate
Dim filePath, oStreamGet, oStreamPut
isValidate = fPassed And CheckFile
If isValidate Then
For i = 0 To itemCount - 1
If Not IsNothing(dataStart(i)) And Not IsNothing(dataLength(i)) Then
If dataLength(i) = 0 Then
itemData(i) = ""
Else
filePath = Server.MapPath(itemData(i))
If CreateFolder("|", ParentFolder(filePath)) Then
Set oStreamGet = Server.CreateObject("ADODB.Stream")
oStreamGet.Type = 1
oStreamGet.Mode = 3
oStreamGet.Open
oStreamGet.Write formData
oStreamGet.Position = dataStart(i)
Set oStreamPut = Server.CreateObject("ADODB.Stream")
oStreamPut.Type = 1
oStreamPut.Mode = 3
oStreamPut.Open
oStreamPut.Write oStreamGet.Read(dataLength(i))
oStreamPut.SaveToFile filePath, 2
oStreamGet.Close
Set oStreamGet = Nothing
oStreamPut.Close
Set oStreamPut = Nothing
End If
End If
End If
Next
IsFinished = True
Else
IsFinished = False
End If
End Function

Private Function CheckFile
Dim oBoolean : oBoolean = True
CheckFile = oBoolean And CheckType And CheckSize
End Function

Private Function CheckType
Dim oBoolean : oBoolean = True
If fileType = "*" Then
oBoolean = oBoolean And True
Else
For i = 0 To itemCount - 1
If Not IsNothing(extenArr(i)) Then
If InStr(1, fileType, "|" & Ucase(Mid(extenArr(i), 2)) & "|") > 0 Then
If fIMGOnly Then
Dim sAllow : sAllow = "|GIF|PJPEG|X-PNG|BMP|"
Dim aCheck : aCheck = Split(UCase(httpArr(i)), "/")
Dim iCheck : iCheck = "|" & aCheck(Ubound(aCheck)) & "|"
If InStr(1, sAllow, iCheck, 1) > 0 Then
oBoolean = oBoolean And True
Else
sErrors = sErrors & "表单 [ " & itemName(i) & " ] 的文件格式错误！\n" & _
"支持的格式为：" & Replace(Mid(fileType, 2, Len(fileType) - 1), "|", " ") & "\n\n"
oBoolean = oBoolean And False
End If
Else
oBoolean = oBoolean And True
End If
Else
sErrors = sErrors & "表单 [ " & itemName(i) & " ] 的文件格式错误！\n" & _
"支持的格式为：" & Replace(Mid(fileType, 2, Len(fileType) - 1), "|", " ") & "\n\n"
oBoolean = oBoolean And False
End If
End If
Next
End If
CheckType = oBoolean
End Function

Private Function CheckSize
Dim oBoolean : oBoolean = True
If fileSize = "*" Then
oBoolean = oBoolean And True
Else
For i = 0 To itemCount - 1
If Not IsNothing(dataLength(i)) Then
Dim tmpSize : tmpSize = CDbl(FormatNumber(CCur(dataLength(i)) / 1024, 2))
If tmpSize <= fileSize Then
oBoolean = oBoolean And True
Else
sErrors = sErrors & "表单 [ " & itemName(i) & " ] 的文件大小 (" & tmpSize & " KB) 超出范围！\n" & _
"支持大小范围：<= " & fileSize & " KB\n\n"
oBoolean = oBoolean And False
End If
End If
Next
End If
CheckSize = oBoolean
End Function

Private Function CreateFolder(byVal sLine, byVal sPath)
Dim oFso
Set oFso = Server.CreateObject("Scripting.FileSystemObject")
If Not oFso.FolderExists(sPath) Then
Dim regEx
Set regEx = New RegExp
regEx.Pattern = "^(.*)\\([^\\]*)$"
regEx.Global = False
regEx.IgnoreCase = True
sLine = sLine & regEx.Replace(sPath, "$2") & "|"
sPath = regEx.Replace(sPath, "$1")
If CreateFolder(sLine, sPath) Then CreateFolder = True
Set regEx = Nothing
Else
If sLine = "|" Then
CreateFolder = True
Else
Dim sTemp : sTemp = Mid(sLine, 2, Len(sLine) - 2)
If InStrRev(sTemp, "|") = 0 Then
sLine = "|"
sPath = sPath & "\" & sTemp
Else
Dim Folder : Folder = Mid(sTemp, InStrRev(sTemp, "|") + 1)
sLine = "|" & Mid(sTemp, 1, InStrRev(sTemp, "|") - 1) & "|"
sPath = sPath & "\" & Folder
End If
oFso.CreateFolder sPath
If CreateFolder(sLine, sPath) Then CreateFolder = True
End if
End If
Set oFso = Nothing
End Function

Private Function ParentFolder(byVal sPath)
Dim regEx
Set regEx = New RegExp
regEx.Pattern = "^(.*)\\[^\\]*$"
regEx.Global = True
regEx.IgnoreCase = True
ParentFolder = regEx.Replace(sPath, "$1")
Set regEx = Nothing
End Function

Private Function IsNothing(byVal sVar)
IsNothing = CBool(sVar = Empty)
End Function

Private Function StrPadLeft(byVal sText, byVal sLen, byVal sChar)
Dim sTemp : sTemp = sText
Do While Len(sTemp) < sLen : sTemp = sChar & sTemp : Loop
StrPadLeft = sTemp
End Function

Private Function StrToByte(byVal sText)
For i = 1 To Len(sText)
StrToByte = StrToByte & ChrB(Asc(Mid(sText, i, 1)))
Next
End Function

Private Function ByteToStr(byVal sByte)
Dim oStream
Set oStream = Server.CreateObject("ADODB.Stream")
oStream.Type = 2
oStream.Mode = 3
oStream.Open
oStream.WriteText sByte
oStream.Position = 0
oStream.CharSet = "gb2312"
oStream.Position = 2
ByteToStr = oStream.ReadText
oStream.Close
Set oStream = Nothing
End Function

Private Function GetClientIPAddr
If IsNothing(GetServerVar("HTTP_X_FORWARDED_FOR")) Then
GetClientIPAddr = GetServerVar("REMOTE_ADDR")
Else
GetClientIPAddr = GetServerVar("HTTP_X_FORWARDED_FOR")
End If
End Function

Private Function GetServerVar(byVal sText)
GetServerVar = Request.ServerVariables(sText)
End Function

Private Function IPToNum(byVal sIp)
Dim sIp_1, sIp_2, sIp_3, sIp_4
If IsNumeric(Left(sIp, 2)) Then
sIp_1 = Left(sIp, InStr(sIp, ".") - 1)
sIp = Mid(sIp, InStr(sIp, ".") + 1)
sIp_2 = Left(sIp, InStr(sIp, ".") - 1)
sIp = Mid(sIp, InStr(sIp, ".") + 1)
sIp_3 = Left(sIp, InStr(sIp, ".") - 1)
sIp_4 = Mid(sIp, InStr(sIp, ".") + 1)
End If
IPToNum = CInt(sIp_1) * 256 * 256 * 256 + CInt(sIp_2) * 256 * 256 + CInt(sIp_3) * 256 + CInt(sIp_4) - 1
End Function

REM CLASS-TERMINATE

Private Sub Class_Terminate
Call DelProgress
Form.RemoveAll
Set Form = Nothing
End Sub

End Class
%>