VB中当charset=UTF-8时base64解码算法，请各位大侠多多指点

[yangyongbo0210]

VB中当charset=UTF-8时base64解码算法，请各位大侠多多指点

[贝隆]

http://wenku.baidu.com/view/91e227717fd5360cba1adb41.html

[贝隆]

http://download.csdn.net/download/leer168/647602

[贝隆]

Private Function funUTF8ToUniCode(ByRef bytUTF8() As Byte) As String
    Dim utfLen As Long
    Dim i As Long
    Dim j As Long
    Dim k As Long
    Dim N As Long
    Dim B As Byte
    Dim cnt As Byte
    Dim Buf() As String
    utfLen = -1
On Error GoTo errFun
    funUTF8ToUniCode = ""
    utfLen = UBound(bytUTF8)
    If utfLen = -1 Then Exit Function

    ReDim Buf(utfLen)
    i = 0
    j = 0
    Do While i <= utfLen
        B = bytUTF8(i)
        If (B And &HFC) = &HFC Then
            cnt = 6
        ElseIf (B And &HF8) = &HF8 Then
            cnt = 5
        ElseIf (B And &HF0) = &HF0 Then
            cnt = 4
        ElseIf (B And &HE0) = &HE0 Then
            cnt = 3
        ElseIf (B And &HC0) = &HC0 Then
            cnt = 2
        Else
            cnt = 1
        End If
        If i + cnt - 1 > utfLen Then
            Buf(j) = "?"
            Exit Do
        End If
        Select Case cnt
            Case 2
                N = B And &H1F
            Case 3
                N = B And &HF
            Case 4
                N = B And &H7
            Case 5
                N = B And &H3
            Case 6
                N = B And &H1
            Case Else
                Buf(j) = Chr(B)
                GoTo Continued:
        End Select
        For k = 1 To cnt - 1
            B = bytUTF8(i + k)
            N = N * &H40 + (B And &H3F)
        Next
        Buf(j) = ChrW(N)
Continued:
        i = i + cnt
        j = j + 1
    Loop
    funUTF8ToUniCode = Join(Buf, "")
errFun:
    
End Function

先用这个函数可以把UTF8转换为UniCode。
然后再解码

[yangyongbo0210]

第二个好像只针对gb2312时base64的解码，请问有没有utf-8时的base64解码，谢谢~！

[贝隆]

其实你搞清楚了原理，怎么搞都无所谓的。

[yangyongbo0210]

我自己弄了个，但是只能还原少量的，如果是大批量的，就会有错误，所以想参考下前辈们的精髓,以来提高自己的见识

[贝隆]

编码，解码最伤脑筋，看的人眼睛发花。呵呵

[yangyongbo0210]

但这也没办法，那玩意也只能糊弄下不懂的人，哎~！可怜的我啊，
我还得找找看有没有前辈们留下来的精髓。

[贝隆]

你快成功了：）

[yangyongbo0210]

谢谢，非常感谢你这几次的回帖

[现在还是人类]

[Quote=引用 8 楼 yangyongbo0210 的回复:]
但这也没办法，那玩意也只能糊弄下不懂的人，哎~！可怜的我啊，
我还得找找看有没有前辈们留下来的精髓。
[/Quote]
最精髓的是去看 PHP 的开源代码，里面有编码和解码函数源代码，当然还有别的值得看的东西