UTF-8轉GB2312函數

<%
'用途:將UTF-8編碼漢字轉換為GB2312碼，兼容英文和數字
'版權:雖說是原創，其實也參考了別人的部分算法
'用法:Response.write UTF2GB("%E9%83%BD%E5%B8%82%E6%83%85%E7%B7%A3 %E6%98%9F%E5%BA%A7")

function UTF2GB(UTFStr)
    for Dig=1 to len(UTFStr)
        if mid(UTFStr,Dig,1)="%" then
            if len(UTFStr) >= Dig+8 then
                GBStr=GBStr & ConvChinese(mid(UTFStr,Dig,9))
                Dig=Dig+8
            else
                GBStr=GBStr & mid(UTFStr,Dig,1)
            end if
        else
            GBStr=GBStr & mid(UTFStr,Dig,1)
        end if
    next
    UTF2GB=GBStr
end function

function ConvChinese(x)
    A=split(mid(x,2),"%")
    i=0
    j=0

    for i=0 to ubound(A)
        A(i)=c16to2(A(i))
    next

    for i=0 to ubound(A)-1
        DigS=instr(A(i),"0")
        Unicode=""
        for j=1 to DigS-1
            if j=1 then
                A(i)=right(A(i),len(A(i))-DigS)
                Unicode=Unicode & A(i)
            else
                i=i+1
                A(i)=right(A(i),len(A(i))-2)
                Unicode=Unicode & A(i)
            end if
        next

        if len(c2to16(Unicode))=4 then
            ConvChinese=ConvChinese & chrw(int("&H" & c2to16(Unicode)))
        else
            ConvChinese=ConvChinese & chr(int("&H" & c2to16(Unicode)))
        end if
    next
end function

function c2to16(x)
    i=1
    for i=1 to len(x)  step 4
        c2to16=c2to16 & hex(c2to10(mid(x,i,4)))
    next
end function

function c2to10(x)
    c2to10=0
    if x="0" then exit function
    i=0
    for i= 0 to len(x) -1
        if mid(x,len(x)-i,1)="1" then c2to10=c2to10+2^(i)
    next
end function

function c16to2(x)
    i=0
    for i=1 to len(trim(x))
        tempstr= c10to2(cint(int("&h" & mid(x,i,1))))
        do while len(tempstr)<4
        tempstr="0" & tempstr
        loop
        c16to2=c16to2 & tempstr
    next
end function

function c10to2(x)
    mysign=sgn(x)
    x=abs(x)
    DigS=1
    do
        if x<2^DigS then
            exit do
        else
            DigS=DigS+1
        end if
    loop
    tempnum=x

    i=0
    for i=DigS to 1 step-1
        if tempnum>=2^(i-1) then
            tempnum=tempnum-2^(i-1)
            c10to2=c10to2 & "1"
        else
            c10to2=c10to2 & "0"
        end if
    next
    if mysign=-1 then c10to2="-" & c10to2
end function
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