VB使用CopyMemory字符串处理

不能直接使用CopyMemoryStr，应该将字符串转为byte数组，然后使用CopyMemory

Property Get item() As String
    If h = 0 Then ErrRaise ERROR_INVALID_DATA
    'BugAssert p <> pNull
    Dim c As Long, ptr0 As Long
    Dim ab() As Byte
    '取出BSTR的长度
    CopyMemory c, ByVal p, 4
    If c > 0 Then
        ReDim ab(c - 1)
        CopyMemory ByVal VarPtr(ab(0)), ByVal (p + 4), c
        item = ab
    End If
End Property

Property Let item(s As String)
    If h = 0 Then ErrRaise ERROR_INVALID_DATA
    'BugAssert p <> pNull
    Dim c As Long
    Dim ab() As Byte
    c = LenB(s)
    ab = s
    ' 重新将BSTR放回内存中
    CopyMemory ByVal p, c, 4
    CopyMemory ByVal (p + 4), ByVal VarPtr(ab(0)), c
End Property