Mymien–风采设计

有时候需要在服务器断判断用户上传上来的图片的长和宽。。比如，你做一个LOGO的连接位置，限定的图片大小为100*100，但如果用户传上的图片LOGO超过了，这个限制，可能前台就觉得很丑了，于是我们可以用以下函数判断获得图片长和宽的函数进行判断：

‘用asp获得图片长和宽的函数

<%
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
%>

函数调用：

<%

    IMGPath=”图片的路径与文件名”
    Set PP=New ImgWHInfo
    pic_width = PP.imgW(Server.Mappath(IMGPath))
    pic_height = PP.imgH(Server.Mappath(IMGPath))
    Set PP=Nothing
%>