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上传图片或显示swf的时候都希望得到它的高度和宽度
基本原理使用adodb.stream读二进制文件然后进行解析，然后返回一数组
第一个元素为类型(bmp jpg png gif swf)
第二个元素为宽度{width}
第三个元素为高度{height}
第四个元素为width={width},height={height}式字符串
class qswhimg
dim aso
private sub class_initialize
set aso=createobject("adodb.stream")
aso.mode=3
aso.type=1
aso.open
end sub
private sub class_terminate
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)
qiushuiwuhen (2002-8-12)
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)
qiushuiwuhen (2002-8-12)
dim ret
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)
qiushuiwuhen (2002-8-12)
dim ret
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)
qiushuiwuhen (2002-8-12)
dim ret
ret = 0
for i = 1 to lenb(bin)
ret = ret *256 + ascb(midb(bin,i,1))
next
binval2=ret
end function
function getimagesize(filespec)
qiushuiwuhen (2002-9-3)
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
end class
使用范例（读某目录下所有图片的宽度）：
set qswh=new qswhimg
set fso = createobject("scripting.filesystemobject")
set f = fso.getfolder(server.mappath("."))
set fc = f.files
for each f1 in fc
ext=fso.getextensionname(f1.path)
select case ext
case "gif","bmp","jpg","png":
arr=qswh.getimagesize(f1.path)
response.write "<br>" & arr(0) & " " & arr(3) & ":" & f1.name & " width:" & arr(1) & " height:" & arr(2)
case "swf"
arr=qswh.getimagesize(f1.path)
response.write "<br>" & arr(0) & " " & arr(3) & ":" & f1.name & " width:" & arr(1) & " height:" & arr(2)
end select
next
set fc=nothing
set f=nothing
set fso=nothing
set qswh=nothing
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