Question

InvalidateRect(hWnd,NULL,FALSE);//FALSE什么意思？

Answer 1

函数原型:
BOOL InvalidateRect(
　　HWND hWnd,
　　CONST RECT *lpRect,
　　BOOL bErase
　　);
MSDN解释:
hWnd : Handle to the window whose update region has changed. If this parameter is NULL, the system invalidates and redraws all windows, and sends the WM_ERASEBKGND and WM_NCPAINT messages to the window procedure before the function returns.
lpRect : Pointer to a RECT structure that contains the client coordinates of the rectangle to be added to the update region. If this parameter is NULL, the entire client area is added to the update region.
bErase :Specifies whether the background within the update region is to be erased when the update region is processed. If this parameter is TRUE, the background is erased when the BeginPaint function is called. If this parameter is FALSE, the background remains unchanged.
bErase :指出无效矩形被标记为有效后，是否重画该区域，重画时用预先定义好的画刷。FALSE表示该区域不重画