关于 directx 7 的 DrawSurface
比如说

Dim BackbufferSurface As DirectDrawSurface7 '定义backbuffersurface
Dim ddsdBackbufferSurface As DDSURFACEDESC2


把BackbufferSurface 作为缓冲面
然后设置
ddsdBackbufferSurface.ddsCaps.lCaps = DDSCAPS_OFFSCREENPLAIN Or DDSCAPS_VIDEOMEMORY


我自己 设置 只要有DDSCAPS_VIDEOMEMORY 这个参数，就崩溃，必须换成 DDSCAPS_SYSTEMMEMORY


这是为什么？

DDSCAPS_SYSTEMMEMORY 明显要比 DDSCAPS_VIDEOMEMORY 慢很多。 求指教~~~~~~
[解决办法]