How to decode UTF8 in VB6?

问题:

I was just wondering if anyone has decoded UTF-8 in VB6? I am having a problem where ANSI 127 and greater are not being properly decoded for whatever reason.

For instance gets decoded into and I'm not sure why.

回答1:

Here's what I've done. Use the MultiByteToWide Char like Comintern said to:

Private Const CP_UTF8 As Long = 65001 ' UTF-8 Code Page  'Sys call to convert multiple byte chars to a char Private Declare Function MultiByteToWideChar Lib "KERNEL32" ( _     ByVal CodePage As Long, _     ByVal dwFlags As Long, _     ByVal lpMultiByteStr As Long, _     ByVal cchMultiByte As Long, _     ByVal lpWideCharStr As Long, _     ByVal cchWideChar As Long) As Long 

Note that I've specified the windows code page, meaning the character set we are working with is UTF-8 Unicode.

Next here is my Decode function. I've called it DecodeURI:

'------------------------------------------------------------------ ' NAME:         DecodeURI (PUBLIC) ' DESCRIPTION:  Decodes a UTF8 encoded string ' CALLED BY:    HandleNavigate ' PARAMETERS: '  EncodedURL (I,REQ) - the UTF-8 encoded string to decode ' RETURNS:      the the decoded UTF-8 string '------------------------------------------------------------------ Private Function DecodeURI(ByVal EncodedURI As String) As String     Dim bANSI() As Byte     Dim bUTF8() As Byte     Dim lIndex As Long     Dim lUTFIndex As Long      If Len(EncodedURI) = 0 Then         Exit Function     End If  EncodedURI = Replace$(EncodedURI, "+", " ")         ' In case encoding isn't used.     bANSI = StrConv(EncodedURI, vbFromUnicode)          ' Convert from unicode text to ANSI values     ReDim bUTF8(UBound(bANSI))                          ' Declare dynamic array, get length     For lIndex = 0 To UBound(bANSI)                     ' from 0 to length of ANSI         If bANSI(lIndex) = &H25 Then                    ' If we have ASCII 37, %, then             bUTF8(lUTFIndex) = Val("&H" & Mid$(EncodedURI, lIndex + 2, 2)) ' convert hex to ANSI             lIndex = lIndex + 2                         ' this character was encoded into two bytes         Else             bUTF8(lUTFIndex) = bANSI(lIndex)            ' otherwise don't need to do anything special         End If         lUTFIndex = lUTFIndex + 1                       ' advance utf index     Next     DecodeURI = FromUTF8(bUTF8, lUTFIndex)              ' convert to string End Function 

And converting from UTF-8 using the system call:

'------------------------------------------------------------------ ' NAME:         FromUTF8 (Private) ' DESCRIPTION:  Use the system call MultiByteToWideChar to '               get chars using more than one byte and return '               return the whole string ' CALLED BY:    DecodeURI ' PARAMETERS: '  UTF8 (I,REQ)   - the ID of the element to return '  Length (I,REQ) - length of the string ' RETURNS:      the full raw data of this field '------------------------------------------------------------------ Private Function FromUTF8(ByRef UTF8() As Byte, ByVal Length As Long) As String     Dim lDataLength As Long      lDataLength = MultiByteToWideChar(CP_UTF8, 0, VarPtr(UTF8(0)), Length, 0, 0)  ' Get the length of the data.     FromUTF8 = String$(lDataLength, 0)                                         ' Create array big enough     MultiByteToWideChar CP_UTF8, 0, VarPtr(UTF8(0)), _                         Length, StrPtr(FromUTF8), lDataLength                  ' End Function 

Hope that helps! I tested it with your character and it appeared to work (as all characters should).

回答2:

Public Function UTF8ENCODE(ByVal sStr As String) As String

For L& = 1 To Len(sStr)

lChar& = AscW(Mid(sStr, L&, 1))

If lChar&

sUtf8$ = sUtf8$ + Mid(sStr, L&, 1)

ElseIf ((lChar& > 127) And (lChar&

sUtf8$ = sUtf8$ + Chr(((lChar& \ 64) Or 192))

sUtf8$ = sUtf8$ + Chr(((lChar& And 63) Or 128))

Else

sUtf8$ = sUtf8$ + Chr(((lChar& \ 144) Or 234))

sUtf8$ = sUtf8$ + Chr((((lChar& \ 64) And 63) Or 128))

sUtf8$ = sUtf8$ + Chr(((lChar& And 63) Or 128))

End If

Next L&

UTF8ENCODE = sUtf8$

End Function

文章来源: How to decode UTF8 in VB6?