利用FSO取得BMP，JPG，PNG，GIF文件信息.

利用FSO取得BMP，JPG，PNG，GIF文件信息. <% '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::: BMP, GIF, JPG and PNG ::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::: ::: '::: This function gets a specified number of bytes from any ::: '::: file, starting at the offset (base 1) ::: '::: ::: '::: Passed: ::: '::: flnm => Filespec of file to read ::: '::: offset => Offset at which to start reading ::: '::: bytes => How many bytes to read ::: '::: ::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: function GetBytes(flnm, offset, bytes) Dim objFSO Dim objFTemp Dim objTextStream Dim lngSize on error resume next Set objFSO = CreateObject("Scripting.FileSystemObject") ' First, we get the filesize Set objFTemp = objFSO.GetFile(flnm) lngSize = objFTemp.Size set objFTemp = nothing fsoForReading = 1 Set objTextStream = objFSO.OpenTextFile(flnm, fsoForReading) if offset > 0 then strBuff = objTextStream.Read(offset - 1) end if if bytes = -1 then ' Get All! GetBytes = objTextStream.Read(lngSize) 'ReadAll else GetBytes = objTextStream.Read(bytes) end if objTextStream.Close set objTextStream = nothing set objFSO = nothing end function '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::: ::: '::: Functions to convert two bytes to a numeric value (long) ::: '::: (both little-endian and big-endian) ::: '::: ::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: function lngConvert(strTemp) lngConvert = clng(asc(left(strTemp, 1)) + ((asc(right(strTemp, 1)) * 256))) end function function lngConvert2(strTemp) lngConvert2 = clng(asc(right(strTemp, 1)) + ((asc(left(strTemp, 1)) * 256))) end function '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::: ::: '::: This function does most of the real work. It will attempt ::: '::: to read any file, regardless of the extension, and will ::: '::: identify if it is a graphical image. ::: '::: ::: '::: Passed: ::: '::: flnm => Filespec of file to read ::: '::: width => width of image ::: '::: height => height of image ::: '::: depth => color depth (in number of colors) ::: '::: strImageType=> type of image (e.g. GIF, BMP, etc.) ::: '::: ::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: function gfxSpex(flnm, width, height, depth, strImageType) dim strPNG dim strGIF dim strBMP dim strType strType = "" strImageType = "(unknown)" gfxSpex = False strPNG = chr(137) & chr(80) & chr(78) strGIF = "GIF" strBMP = chr(66) & chr(77) strType = GetBytes(flnm, 0, 3) if strType = strGIF then ' is GIF strImageType = "GIF" Width = lngConvert(GetBytes(flnm, 7, 2)) Height = lngConvert(GetBytes(flnm, 9, 2)) Depth = 2 ^ ((asc(GetBytes(flnm, 11, 1)) and 7) + 1) gfxSpex = True elseif left(strType, 2) = strBMP then ' is BMP strImageType = "BMP" Width = lngConvert(GetBytes(flnm, 19, 2)) Height = lngConvert(GetBytes(flnm, 23, 2)) Depth = 2 ^ (asc(GetBytes(flnm, 29, 1))) gfxSpex = True elseif strType = strPNG then ' Is PNG strImageType = "PNG" Width = lngConvert2(GetBytes(flnm, 19, 2)) Height = lngConvert2(GetBytes(flnm, 23, 2)) Depth = getBytes(flnm, 25, 2) select case asc(right(Depth,1)) case 0 Depth = 2 ^ (asc(left(Depth, 1))) gfxSpex = True case 2 Depth = 2 ^ (asc(left(Depth, 1)) * 3) gfxSpex = True case 3 Depth = 2 ^ (asc(left(Depth, 1))) '8 gfxSpex = True case 4 Depth = 2 ^ (asc(left(Depth, 1)) * 2) gfxSpex = True case 6 Depth = 2 ^ (asc(left(Depth, 1)) * 4) gfxSpex = True case else Depth = -1 end select else strBuff = GetBytes(flnm, 0, -1) ' Get all bytes from file lngSize = len(strBuff) flgFound = 0 strTarget = chr(255) & chr(216) & chr(255) flgFound = instr(strBuff, strTarget) if flgFound = 0 then exit function end if strImageType = "JPG" lngPos = flgFound + 2 ExitLoop = false do while ExitLoop = False and lngPos < lngSize do while asc(mid(strBuff, lngPos, 1)) = 255 and lngPos < lngSize lngPos = lngPos + 1 loop if asc(mid(strBuff, lngPos, 1)) < 192 or asc(mid(strBuff, lngPos, 1)) > 195 then lngMarkerSize = lngConvert2(mid(strBuff, lngPos + 1, 2)) lngPos = lngPos + lngMarkerSize + 1 else ExitLoop = True end if loop ' if ExitLoop = False then Width = -1 Height = -1 Depth = -1 else Height = lngConvert2(mid(strBuff, lngPos + 4, 2)) Width = lngConvert2(mid(strBuff, lngPos + 6, 2)) Depth = 2 ^ (asc(mid(strBuff, lngPos + 8, 1)) * 8) gfxSpex = True end if end if end function '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: '::: Test Harness ::: '::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ' To test, we'll just try to show all files with a .GIF extension in the root of C: Set objFSO = CreateObject("Scripting.FileSystemObject") Set objF = objFSO.GetFolder("c:\") Set objFC = objF.Files response.write "<table border=""0"" cellpadding=""5"">" For Each f1 in objFC if instr(ucase(f1.Name), ".GIF") then response.write "<tr><td>" & f1.name & "</td><td>" & f1.DateCreated & "</td><td>" & f1.Size & "</td><td>" if gfxSpex(f1.Path, w, h, c, strType) = true then response.write w & " x " & h & " " & c & " colors" else response.write " " end if response.write "</td></tr>" end if Next response.write "</table>" set objFC = nothing set objF = nothing set objFSO = nothing %>