ASP中取得图片宽度与高度的类（无组件）

<%
Class ImgWHInfo '获取图片宽度和高度的类，支持JPG，GIF，PNG，BMP
    Dim ASO
    Private Sub Class_Initialize
        Set ASO=Server.CreateObject("ADODB.Stream")
        ASO.Mode=3
        ASO.Type=1
        ASO.Open
    End Sub
    Private Sub Class_Terminate
        Err.Clear
        Set ASO=Nothing
    End Sub
 
    Private Function Bin2Str(Bin)
        Dim I, Str
        For I=1 To LenB(Bin)
            clow=MidB(Bin,I,1)
            If ASCB(clow)<128 Then
                Str = Str & Chr(ASCB(clow))
            Else
                I=I+1
                If I <= LenB(Bin) Then Str = Str & Chr(ASCW(MidB(Bin,I,1)&clow))
            End If
        Next
        Bin2Str = Str
    End Function
     
    Private Function Num2Str(Num,Base,Lens)
        Dim Ret
        Ret = ""
        While(Num>=Base)
            Ret = (Num Mod Base) & Ret
            Num = (Num - Num Mod Base)/Base
        Wend
        Num2Str = Right(String(Lens,"0") & Num & Ret,Lens)
    End Function
     
    Private Function Str2Num(Str,Base)
        Dim Ret,I
        Ret = 0
        For I=1 To Len(Str)
            Ret = Ret *base + Cint(Mid(Str,I,1))
        Next
        Str2Num=Ret
    End Function
     
    Private Function BinVal(Bin)
        Dim Ret,I
        Ret = 0
        For I = LenB(Bin) To 1 Step -1
            Ret = Ret *256 + AscB(MidB(Bin,I,1))
        Next
        BinVal=Ret
    End Function
     
    Private Function BinVal2(Bin)
        Dim Ret,I
        Ret = 0
        For I = 1 To LenB(Bin)
            Ret = Ret *256 + AscB(MidB(Bin,I,1))
        Next
        BinVal2=Ret
    End Function
     
    Private Function GetImageSize(filespec)
        Dim bFlag
        Dim Ret(3)
        ASO.LoadFromFile(filespec)
        bFlag=ASO.Read(3)
        Select Case Hex(binVal(bFlag))
        Case "4E5089":
            ASO.Read(15)
            ret(0)="PNG"
            ret(1)=BinVal2(ASO.Read(2))
            ASO.Read(2)
            ret(2)=BinVal2(ASO.Read(2))
        Case "464947":
            ASO.read(3)
            ret(0)="gif"
            ret(1)=BinVal(ASO.Read(2))
            ret(2)=BinVal(ASO.Read(2))
        Case "535746":
            ASO.read(5)
            binData=ASO.Read(1)
            sConv=Num2Str(ascb(binData),2 ,8)
            nBits=Str2Num(left(sConv,5),2)
            sConv=mid(sConv,6)
            While(len(sConv)<nBits*4)
                binData=ASO.Read(1)
                sConv=sConv&Num2Str(AscB(binData),2 ,8)
            Wend
            ret(0)="SWF"
            ret(1)=Int(Abs(Str2Num(Mid(sConv,1*nBits+1,nBits),2)-Str2Num(Mid(sConv,0*nBits+1,nBits),2))/20)
            ret(2)=Int(Abs(Str2Num(Mid(sConv,3*nBits+1,nBits),2)-Str2Num(Mid(sConv,2*nBits+1,nBits),2))/20)
        Case "FFD8FF":
            Do 
            Do: p1=binVal(ASO.Read(1)): Loop While p1=255 And Not ASO.EOS
            If p1>191 And p1<196 Then Exit Do Else ASO.read(binval2(ASO.Read(2))-2)
            Do:p1=binVal(ASO.Read(1)):Loop While p1<255 And Not ASO.EOS
            Loop While True
            ASO.Read(3)
            ret(0)="JPG"
            ret(2)=binval2(ASO.Read(2))
            ret(1)=binval2(ASO.Read(2))
        Case Else:
            If left(Bin2Str(bFlag),2)="BM" Then
                ASO.Read(15)
                ret(0)="BMP"
                ret(1)=binval(ASO.Read(4))
                ret(2)=binval(ASO.Read(4))
            Else
                    ret(0)=""
            End If
        End Select
        ret(3)="width=""" & ret(1) &""" height=""" & ret(2) &""""
        getimagesize=ret
    End Function
     
    Public Function imgW(IMGPath)
        Dim FSO,IMGFile,FileExt,Arr
        Set FSO = Server.CreateObject("Scripting.FileSystemObject")
        If (FSO.FileExists(IMGPath)) Then
            Set IMGFile = FSO.GetFile(IMGPath)
            FileExt=FSO.GetExtensionName(IMGPath)
            Select Case FileExt
                Case "gif","bmp","jpg","png":
                Arr=GetImageSize(IMGFile.Path)
                imgW = Arr(1)
            End Select
            Set IMGFile=Nothing
        Else
            imgW = 0
        End If    
        Set FSO=Nothing
    End Function
    
    Public Function imgH(IMGPath)
        Dim FSO,IMGFile,FileExt,Arr
        Set FSO = server.CreateObject("Scripting.FileSystemObject")
        If (FSO.FileExists(IMGPath)) Then
            Set IMGFile = FSO.GetFile(IMGPath)
            FileExt=FSO.GetExtensionName(IMGPath)
            Select Case FileExt
                Case "gif","bmp","jpg","png":
                Arr=getImageSize(IMGFile.Path)
                imgH = Arr(2)
            End Select
            Set IMGFile=Nothing
        Else
            imgH = 0
        End If    
        Set FSO=Nothing
    End Function
End Class

IMGPath="Test.jpg"

Set PP = New ImgWHInfo 
W = PP.imgW(Server.Mappath(IMGPath)) 
H = PP.imgH(Server.Mappath(IMGPath))
Set pp = Nothing
 
Response.Write("<img src='"&IMGPath&"' border=0><br>宽:"&W&";高:"&H)
%>