Asp classic 如何使用服务器端vbscript获取图像宽度?Asp经典
几天来,我一直在寻找一种方法来获取驻留在服务器上的.png文件的图像宽度。我试图读取文件的前24个字节,并从字节17-20解析出宽度。我在网上找到了好几个程序,但都没有成功。奇怪的是,我似乎得到了从十六进制到十进制解码的字节21-24的高度。我已经验证了文件内容使用十六进制查看器和文件是好的。以下是例行程序的主要部分:Asp classic 如何使用服务器端vbscript获取图像宽度?Asp经典,asp-classic,vbscript,Asp Classic,Vbscript,几天来,我一直在寻找一种方法来获取驻留在服务器上的.png文件的图像宽度。我试图读取文件的前24个字节,并从字节17-20解析出宽度。我在网上找到了好几个程序,但都没有成功。奇怪的是,我似乎得到了从十六进制到十进制解码的字节21-24的高度。我已经验证了文件内容使用十六进制查看器和文件是好的。以下是例行程序的主要部分: Function ReadPNG(fichero) Dim fso, ts, s, HW, nbytes HW = Array("0", "0") Set fso
Function ReadPNG(fichero)
Dim fso, ts, s, HW, nbytes
HW = Array("0", "0")
Set fso = CreateObject("Scripting.FileSystemObject")
Set ts = fso.OpenTextFile(Server.MapPath("\forums\attachments/" & fichero), 1)
s = Right(ts.Read(24), 8)
HW(0) = HexToDec(HexAt(s,3) & HexAt(s,4))
HW(1) = HexToDec(HexAt(s,7) & HexAt(s,8))
ts.Close
ReadPNG = HW
End Function
Function HexAt(s, n)
HexAt = Hex(AscAt(s, n))
End Function
Function HexToDec(ByVal HexVal)
Dim i, num, part
num = 0
For I = 1 to Len(HexVal)
part = Mid(StrReverse(UCase(HexVal)), I, 1)
If IsNumeric(part) Then
num = num + (CInt(part) * 16 ^ (I - 1) )
Else
num = num + ( (Asc(part) - 55) * 16^(I - 1) )
End If
Next
HexToDec = num
End Function
例如,我的文件的宽度字节中有十六进制“00 00 01 80”(十进制384)
和十六进制“00 00 01 32”的高度字节(十进制306)
我得到的是高度306,但宽度返回“0011”(十进制17)
我完全被绊倒了!我也不必使用这个例程
谢谢,
Jim这是我刚才看到的一篇帖子,看起来它可能会简化一些事情。我还没有测试,所以让我知道你的结果
<%
dim iWidth, iheight
sub ImgDimension(img)
dim myImg, fs
Set fs= CreateObject("Scripting.FileSystemObject")
if not fs.fileExists(img) then exit sub
set myImg = loadpicture(img)
iWidth = round(myImg.width / 26.4583)
iheight = round(myImg.height / 26.4583)
set myImg = nothing
end sub
ImgDimension(Server.MapPath("server image file"))
%>
请参见此处查看帖子:
更新:看到此方法在64位中不起作用。这里是另一个可选方法的链接:这里是我多年前发现的一组用于获取图像信息的通用函数。我会把我一直使用的方式放在最后
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: :::'
'::: This routine will attempt to identify any filespec passed :::'
'::: as a graphic file (regardless of the extension). This will :::'
'::: work with BMP, GIF, JPG and PNG files. :::'
'::: :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: Based on ideas presented by David Crowell :::'
'::: (credit where due) :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: blah blah blah blah blah blah blah blah blah blah blah blah :::'
'::: blah blah blah blah blah blah blah blah blah blah blah blah :::'
'::: blah blah Copyright *c* MM, Mike Shaffer blah blah :::'
'::: blah blah ALL RIGHTS RESERVED WORLDWIDE blah blah :::'
'::: blah blah Permission is granted to use this code blah blah :::'
'::: blah blah in your projects, as long as this blah blah :::'
'::: blah blah copyright notice is included blah blah :::'
'::: blah blah blah blah blah blah blah blah blah blah blah blah :::'
'::: blah blah blah blah blah blah blah blah blah blah blah blah :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: :::'
'::: 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
”:
'::: :::'
“:::此例程将尝试标识传递的任何文件规范::”
'::作为图形文件(不考虑扩展名)。这将::'
':::使用BMP、GIF、JPG和PNG文件。:'
'::: :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
“:::基于大卫·克劳威尔提出的想法:”
“:(到期时贷记):”
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
’:::废话废话废话废话废话废话废话:废话
’:::废话废话废话废话废话废话废话:废话
’:::诸如此类版权所有*c*MM,迈克·沙弗诸如此类::'
’:::诸如此类,版权所有。诸如此类::'
“:::诸如此类的权限被授予使用此代码诸如此类的:::”
’:::在你的项目中胡说八道,只要这个胡说八道::'
“:::诸如此类的版权声明包括在内诸如此类的::”
’:::废话废话废话废话废话废话废话:废话
’:::废话废话废话废话废话废话废话:废话
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: :::'
“:::此函数从任何::”中获取指定数量的字节
“:::文件,从偏移量开始(基1):”
'::: :::'
“:::已通过::”
':::flnm=>Filespec要读取的文件::'
“:::offset=>开始读取的偏移量::”
“:::bytes=>要读取的字节数::”
'::: :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
函数GetBytes(flnm、偏移量、字节)
Dim objFSO
模糊对象
暗淡的objTextStream
模糊lngSize
出错时继续下一步
设置objFSO=CreateObject(“Scripting.FileSystemObject”)
'首先,我们获得文件大小'
设置objFTemp=objFSO.GetFile(flnm)
lngSize=objFTemp.Size
设置objFTemp=nothing
fsoForReading=1
设置objTextStream=objFSO.OpenTextFile(flnm、fsoForReading)
如果偏移量>0,则
strBuff=objTextStream.Read(偏移量-1)
如果结束
如果字节=-1,则“全部获取!”
GetBytes=objTextStream.Read(lngSize)'ReadAll'
其他的
GetBytes=objTextStream.Read(字节)
如果结束
objTextStream,关闭
设置objTextStream=nothing
设置objFSO=nothing
端函数
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: :::'
“:::函数,用于将两个字节转换为数值(长):”
“::(小端和大端):”
'::: :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
功能lngConvert(strTemp)
lngConvert=clng(asc(左(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(
端函数
功能lngConvert2(strTemp)
lngConvert2=clng(asc(右(右(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右)(右
端函数
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
'::: :::'
'::此函数完成大部分实际工作。它将尝试::'
“:::读取任何文件,无论其扩展名为何,并将::”
':::标识它是否是图形图像。:'
'::: :::'
“:::已通过::”
':::flnm=>Filespec要读取的文件::'
“:::width=>图像的宽度::”
“:::height=>图像的高度::”
“:::depth=>颜色深度(以颜色数表示):”
“:::strImageType=>图像类型(例如GIF、BMP等):”
'::: :::'
':::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::'
函数gfxSpex(flnm
'collect the image information into an array'
Dim blnGfxSpex, width, height, colors, strType
intCount = 0
For Each objFile In objFS.GetFolder(".\images").Files
If LCase(Right(objFile.Name, 4)) = ".jpg" and intCount <= intNumOfFiles Then
blnGfxSpex = gfxSpex((".\images\" & objFile.Name), width, height, colors, strType)
arrImages(intCount) = "<image>" & vbNewLine & _
"<filename>" & objFile.Name & "</filename>" & vbNewLine & _
"<caption></caption>" & vbNewLine & _
"<width>" & width & "</width>" & vbNewLine & _
"<height>" & height & "</height>" & vbNewLine & _
"</image>" & vbNewLine
intCount = intCount + 1
End If
Next
Function ImgDim(img)
Dim objFSO, objGF, objLP, imgWdt, imgHgt, imgSiz
img = Server.MapPath("/pictures/"& img) 'path to picture
Set objFSO= CreateObject("Scripting.FileSystemObject")
If objFSO.fileExists(img) Then
Set objGF = objFSO.GetFile(img)
imgSiz = objGF.Size
Set objGF = Nothing
Set objLP = loadpicture(img)
imgWdt = round(objLP.width / 26.4583)
imgHgt = round(objLP.height / 26.4583)
Set objLP = Nothing
Set fs = Nothing
ImgDim = imgWdt &"x"& imgHgt &" - "& imgSiz/1024 &"KBytes"
End If
End Function