我的ASP之旅—无组件生成缩略图-ASP教程,组件开发

<%
//////////// gps：get picture size //////////////
//////////////利用adodb.stream获取图片尺寸//////////////
/////////cited by leon（心晴） 2005年8月11日//////////
class gps
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)
gps (2005-8-11)
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)
gps (2005-8-11)
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)
gps (2002-8-11)
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)
gps (2002-8-11)
dim ret
ret = 0
for i = 1 to lenb(bin)
ret = ret *256 + ascb(midb(bin,i,1))
next
binval2=ret
end function

///以下是调用代码///
function getimagesize(filespec)
gps (2002-8-11)
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
%>

将以上代码复制生成gps.asp文件，这样无组件获取图片尺寸的通用类就ok了。

 图片：

 图片格式：

 图片尺寸：

 图片大小：

 点击次数：

<% 
 /////获取showimg.asp的绝对路径/////
 dim curfile
 curfile=server.mappath(request.servervariables(“path_info”))
  
 dim curfilename,filename

 /////图片相对路径（存于数据库中）
 cufilename=rs(“imgurl”)
 /////因为showimg.asp与images在同一目录，所以我们用instrrev获取images的路径/////
 filename=left(curfile,instrrev(curfile,”\”))&cufilename
    
 /////建立gps类实体/////
 dim getpicsize
 set getpicsize=new gps
 
 set fs=server.createobject(“scripting.filesystemobject”)
 /////获取图片类型/////
 dim picsuffixname
 picsuffixname=fs.getextensionname(filename)
 
 dim pd //picture dimension
 dim pwidth,pheight
 
 select case picsuffixname
 case “gif”,”bmp”,”jpg”,”png”:
 /////调用gps通用类中的getimagesize函数获取图片尺寸/////
 pd=getpicsize.getimagesize(filename)
 pwidth=pd(1)   //获取图片宽度
 pheight=pd(2)  //获取图片高度
 case “swf”
 pd=getpicsize.getimagesize(filename)
 pwidth=pd(1)  //获取flash宽度
 pheight=pd(2) //获取flash高度
 case else
 end select
 
 set fs=nothing
 set getpicsize=nothing
 %>