音量框顯示一段時間後，讓顯示消失

        nowtime = mapi_time_utility::GetTime0();
        if(nowtime - pretime > 1000 && volume_surface != NULL)
        {
            DFBRegion subRegion;
            subRegion.x1 = (int)(WIDTH - IMAGE_WIDTH) / 2;
            subRegion.y1 = (int)(HEIGHT - IMAGE_HEIGHT) / 2;
            subRegion.x2= (int)IMAGE_WIDTH;
            subRegion.y2 = (int)IMAGE_HEIGHT;


            volume_surface->SetColor(volume_surface,0x00,0x00,0x00,0x00);
            volume_surface->FillRectangle(volume_surface, subRegion.x1, subRegion.y1, subRegion.x2, subRegion.y2);
            volume_surface->Flip(volume_surface, (const DFBRegion*)&subRegion, (DFBSurfaceFlipFlags)0);
        }