ASP URL反编码函数代码

网络整理 - 09-08

　　例如:

　　我们在百度中搜索脚本之家，则网址后面的参数就是

　　?cl=3&wd=%BD%C5%B1%BE%D6%AE%BC%D2

　　如果我们想将%BD%C5%B1%BE%D6%AE%BC%D2还原为中文，使用下面的函数即可。

　　response.write urldecode("?cl=3&wd=%BD%C5%B1%BE%D6%AE%BC%D2")

　　'================================================

　　'函数名：URLDecode

　　'作用：URL解码

　　'================================================

　　Function URLDecode(ByVal urlcode)

　　Dim start,final,length,char,i,butf8,pass

　　Dim leftstr,rightstr,finalstr

　　Dim b0,b1,bx,blength,position,u,utf8

　　On Error Resume Next

　　b0 = Array(192,224,240,248,252,254)

　　urlcode = Replace(urlcode,"+"," ")

　　pass = 0

　　utf8 = -1

　　length = Len(urlcode) : start = InStr(urlcode,"%") : final = InStrRev(urlcode,"%")

　　If start = 0 Or length < 3 Then URLDecode = urlcode : Exit Function

　　leftstr = Left(urlcode,start - 1) : rightstr = Right(urlcode,length - 2 - final)

　　For i = start To final

　　char = Mid(urlcode,i,1)

　　If char = "%" Then

　　bx = URLDecode_Hex(Mid(urlcode,i + 1,2))

　　If bx > 31 And bx < 128 Then

　　i = i + 2

　　finalstr = finalstr & ChrW(bx)

　　ElseIf bx > 127 Then

　　i = i + 2

　　If utf8 < 0 Then

　　butf8 = 1 : blength = -1 : b1 = bx

　　For position = 4 To 0 Step -1

　　If b1 >= b0(position) And b1 < b0(position + 1) Then

　　blength = position

　　Exit For

　　End If

　　If blength > -1 Then

　　For position = 0 To blength

　　b1 = URLDecode_Hex(Mid(urlcode,i + position * 3 + 2,2))

　　If b1 < 128 Or b1 > 191 Then butf8 = 0 : Exit For

　　Else

　　butf8 = 0

　　End If

　　If butf8 = 1 And blength = 0 Then butf8 = -2

　　If butf8 > -1 And utf8 = -2 Then i = start - 1 : finalstr = "" : pass = 1

　　utf8 = butf8

　　End If

　　If pass = 0 Then

　　If utf8 = 1 Then

　　b1 = bx : u = 0 : blength = -1

　　For position = 4 To 0 Step -1

　　If b1 >= b0(position) And b1 < b0(position + 1) Then

　　blength = position

　　b1 = (b1 xOr b0(position)) * 64 ^ (position + 1)

　　Exit For

　　End If

　　If blength > -1 Then

　　For position = 0 To blength

　　bx = URLDecode_Hex(Mid(urlcode,i + 2,2)) : i = i + 3

　　If bx < 128 Or bx > 191 Then u = 0 : Exit For

　　u = u + (bx And 63) * 64 ^ (blength - position)

　　If u > 0 Then finalstr = finalstr & ChrW(b1 + u)

　　End If

　　Else

　　b1 = bx * &h100 : u = 0

　　bx = URLDecode_Hex(Mid(urlcode,i + 2,2))

　　If bx > 0 Then

　　u = b1 + bx

　　i = i + 3

　　Else

　　If Left(urlcode,1) = "%" Then

　　u = b1 + Asc(Mid(urlcode,i + 3,1))

　　i = i + 2

　　Else

　　u = b1 + Asc(Mid(urlcode,i + 1,1))

　　i = i + 1

　　End If

　　finalstr = finalstr & Chr(u)

　　End If

　　Else

　　pass = 0

　　End If

　　Else

　　finalstr = finalstr & char

　　End If

　　URLDecode = leftstr & finalstr & rightstr

　　End Function

　　Function URLDecode_Hex(ByVal h)

　　On Error Resume Next

　　h = "&h" & Trim(h) : URLDecode_Hex = -1

　　If Len(h) <> 4 Then Exit Function

　　If isNumeric(h) Then URLDecode_Hex = cInt(h)

　　End Function