PAINTSTRUCT ps;是什么意思？？

是一个绘图信息结构，这是MSDN里的详尽解释，还有什么问题我再帮你查：
typedef struct tagPAINTSTRUCT {
HDC hdc;
BOOL fErase;
RECT rcPaint;
BOOL fRestore;
BOOL fIncUpdate;
BYTE rgbReserved[32];
} PAINTSTRUCT, *PPAINTSTRUCT;
Members
hdc
Handle to the display DC to be used for painting.
fErase
Specifies whether the background must be erased. This value is nonzero if the application should erase the background. The application is responsible for erasing the background if a window class is created without a background brush. For more information, see the description of the hbrBackground member of the WNDCLASS structure.
rcPaint
Specifies a RECT structure that specifies the upper left and lower right corners of the rectangle in which the painting is requested, in device units relative to the upper-left corner of the client area.
fRestore
Reserved; used internally by the system.
fIncUpdate
Reserved; u