报错语句：
TimerID = SetTimer(FormHwnd, 0, 100, AddressOf TimerProc)

相关语句：
    Public Declare Function SetTimer Lib "user32" (ByVal hwnd As Int32, ByVal nIDEvent As Int32, ByVal uElapse As Int32, ByVal lpTimerFunc As Int32) As Int32
   
Sub TimerProc(ByVal hwnd As Int32, ByVal uMsg As Int32, ByVal idEvent As Int32, ByVal lngSysTime As Int32)
        Dim OldMousePos As POINTAPI, NewMousePos As POINTAPI

        Dim FormRECT As RECT
        Dim FormWidth As Int32, FormHeight As Int32
        GetCursorPos(NewMousePos)
        If NewMousePos.x = OldMousePos.x And NewMousePos.y = OldMousePos.y Then Exit Sub
        OldMousePos = NewMousePos
        GetWindowRect(FormHwnd, FormRECT)
        FormDC = GetWindowDC(FormHwnd)
        DeskDC = GetWindowDC(0)
        FormWidth = FormRECT.Right - FormRECT.Left
        FormHeight = FormRECT.Bottom - FormRECT.Top
        UpdateWindow(FormHwnd)
        StretchBlt(FormDC, 0, 0, FormWidth, FormHeight, DeskDC, NewMousePos.x - FormWidth / 2 / ZoomCount, NewMousePos.y - FormHeight / 2 / ZoomCount, FormWidth / ZoomCount, FormHeight / ZoomCount, SRCCOPY)
        ReleaseDC(FormHwnd, FormDC)
        ReleaseDC(0, DeskDC)
    End Sub
感谢能有高手指点下。