BitBlt (hdcBmp, 0,0,1920,1440, hdcEnemy, 0, 0, SRCCOPY);//background copy 

The Draw (hdcBmp);//background in the painting is not mobile homes trees such as 

BitBlt (hdcBack, 0, 0, g_rc. Right, g_rc. Bottom, hdcBmp, mapx, mapy, SRCCOPY);//have a good background copy 

Draw1 (hdcBack);//painting will move people, etc. 

BitBlt (HDC, 0, 0, g_rc. Right, g_rc. Bottom, hdcBack, 0, 0, SRCCOPY);//display on the screen 

I always do not display background according to the above method, and houses, will only display, the background is all black, how be to return a responsibility excuse me?