excel - 获取 charcode 值大于十六进制 `FFFF` 的 Unicode 字符

Question

问题

ChrW charcode 参数是一个 Long，用于标识字符，但不允许值大于 65535(十六进制值 &HFFFF) -请参阅MS Help .

例如，各种符号和象形文字可以在 Unicode 十六进制 block 1F300-1F5FF 中找到。因此，我没有找到任何方法来表示打开或关闭的挂锁符号的 ►1F512 和 1F513 的建议十六进制值正是在这个字符代码块中，当然ChrW(&H1F512)将导致无效的过程/参数调用。

最近的 answer发现一个可能不稳定的替代方案，涉及较低的字符代码(通过 ChrW(&HE1F7) 和 ChrW(&HE1F6))，但我正在寻找一种获得更高字符码表示的方法。

问题

是否有一种系统方法可以通过 VBA 或解决方法来表达大于 FFFF 的十六进制代码块中的 Unicode 字符？

Answer 1

像这样的东西应该可以工作。大多数代码不是我写的，但我知道要寻找什么。基本上将十六进制映射到等效的字节数组，然后取回字符串。

 Option Explicit

'Pulled from https://www.di-mgt.com.au/howto-convert-vba-unicode-to-utf8.html
''' Maps a character string to a UTF-16 (wide character) string
Private Declare PtrSafe Function MultiByteToWideChar Lib "kernel32" ( _
ByVal CodePage As Long, _
ByVal dwFlags As Long, _
ByVal lpMultiByteStr As LongPtr, _
ByVal cchMultiByte As Long, _
ByVal lpWideCharStr As LongPtr, _
ByVal cchWideChar As Long _
) As Long

' CodePage constant for UTF-8
Private Const CP_UTF8 = 65001

''' Return length of byte array or zero if uninitialized
Private Function BytesLength(abBytes() As Byte) As Long
    ' Trap error if array is uninitialized
    On Error Resume Next
    BytesLength = UBound(abBytes) - LBound(abBytes) + 1
End Function

''' Return VBA "Unicode" string from byte array encoded in UTF-8
Public Function Utf8BytesToString(abUtf8Array() As Byte) As String
    Dim nBytes As Long
    Dim nChars As Long
    Dim strOut As String
    Utf8BytesToString = ""
    ' Catch uninitialized input array
    nBytes = BytesLength(abUtf8Array)
    If nBytes <= 0 Then Exit Function
    ' Get number of characters in output string
    nChars = MultiByteToWideChar(CP_UTF8, 0&, VarPtr(abUtf8Array(0)), nBytes, 0&, 0&)
    ' Dimension output buffer to receive string
    strOut = String(nChars, 0)
    nChars = MultiByteToWideChar(CP_UTF8, 0&, VarPtr(abUtf8Array(0)), nBytes, StrPtr(strOut), nChars)
    Utf8BytesToString = Left$(strOut, nChars)
End Function

'Grabbed from https://stackoverflow.com/questions/28798759/how-convert-hex-string-into-byte-array-in-vb6
Private Function HexToBytes(ByVal HexString As String) As Byte()
    'Quick and dirty hex String to Byte array.  Accepts:
    '
    '   "HH HH HH"
    '   "HHHHHH"
    '   "H HH H"
    '   "HH,HH,     HH" and so on.

    Dim Bytes() As Byte
    Dim HexPos As Integer
    Dim HexDigit As Integer
    Dim BytePos As Integer
    Dim Digits As Integer

    ReDim Bytes(Len(HexString) \ 2)  'Initial estimate.
    For HexPos = 1 To Len(HexString)
        HexDigit = InStr("0123456789ABCDEF", _
                         UCase$(Mid$(HexString, HexPos, 1))) - 1
        If HexDigit >= 0 Then
            If BytePos > UBound(Bytes) Then
                'Add some room, we'll add room for 4 more to decrease
                'how often we end up doing this expensive step:
                ReDim Preserve Bytes(UBound(Bytes) + 4)
            End If
            Bytes(BytePos) = Bytes(BytePos) * &H10 + HexDigit
            Digits = Digits + 1
        End If
        If Digits = 2 Or HexDigit < 0 Then
            If Digits > 0 Then BytePos = BytePos + 1
            Digits = 0
        End If
    Next
    If Digits = 0 Then BytePos = BytePos - 1
    If BytePos < 0 Then
        Bytes = "" 'Empty.
    Else
        ReDim Preserve Bytes(BytePos)
    End If
    HexToBytes = Bytes
End Function

调用示例

Public Sub ExampleLock()
    Dim LockBytes()  As Byte
    LockBytes = HexToBytes("F0 9F 94 92") ' Lock Hex representation, found by -->http://www.ltg.ed.ac.uk/~richard/utf-8.cgi
    Sheets(1).Range("A1").Value = Utf8BytesToString(LockBytes) ' Output
End Sub

这是输出到 A1 的内容。