用下面的API就好了
Public Declare Function InvalidateRect Lib "user32" Alias "InvalidateRect" (ByVal hwnd As Long, lpRect As RECT, ByVal bErase As Long) As Long
Public Declare Function TextOut Lib "gdi32" Alias "TextOutA" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal lpString As String, ByVal nCount As Long) As Long