如何实现用directX在屏幕上显示一个bmp图片,我写了一段代码，但是执行起来就花屏，360度转体跪求解决方法！

大家能帮我看看程序吗？非常感谢！
如果能解决我的问题，我将感激涕零！55555555555！郁闷好多天了！
代码如下：
#include <windows.h>
#include <windowsx.h>
#include <ddraw.h>
#include "Ddutil.h"
#include "Ddutil.cpp"
LPDIRECTDRAW lpdd;//DIRECTDRAW对象
LPDIRECTDRAWSURFACE lpddsprimary;//主表面对象，即屏幕显示的表面
LPDIRECTDRAWSURFACE lpddsback;//后台表面，主表面要翻转的表面
LPDIRECTDRAWSURFACE lpddsoffscreen;//离屏表面，存放图像的表面
LPDIRECTDRAWPALETTE lpddpal;//调色板

char showline[] = "hello world";
BOOL bActive = TRUE;
HDC hdc;
RECT rect;
//函数声明
void MainGame(void);
BOOL InitDDraw(void);
void FreeDDraw(void);


LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
HWND hwnd;
MSG Msg;
WNDCLASS wndclass;
char lpszClassName[] = "window";
char lpszTitle[] = "my_window";

wndclass.style = 0;
wndclass.lpfnWndProc = WndProc;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hInstance = hInstance;
wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
wndclass.lpszMenuName = NULL;
wndclass.lpszClassName = lpszClassName;


if(!RegisterClass(&wndclass))
{
MessageBeep(0);
return FALSE;

}

hwnd = CreateWindow(lpszClassName,
lpszTitle,
WS_POPUP,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
NULL);

ShowWindow(hwnd, nShowCmd);
UpdateWindow(hwnd);

if(!InitDDraw())
{
MessageBox(GetActiveWindow(), "initDDrawwERR", "ERR", MB_OK);
FreeDDraw();
DestroyWindow(GetActiveWindow());
return FALSE;
}


while(1)
{
if(PeekMessage(&Msg, NULL, 0, 0, PM_NOREMOVE))
{
if(!GetMessage(&Msg, NULL, 0, 0))
return Msg.wParam;
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
else if(bActive)
{
MainGame();
}
}

}

//消息函数
LRESULT CALLBACK WndProc(HWND hwnd,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
switch(message)
{
case WM_CREATE:
ShowCursor(false);
bActive = true;
case WM_KEYDOWN:
switch(wParam)
{
case VK_ESCAPE:
PostMessage(hwnd, WM_CLOSE, 0, 0);
break;
}
break;
case WM_DESTROY:

PostQuitMessage(0);
default:
return DefWindowProc(hwnd, message, wParam, lParam);

}
return (0);
}

//初始化DirectDraw
BOOL InitDDraw(void)
{
DDSURFACEDESC ddsd;
DDSCAPS ddscaps;
DDSURFACEDESC ddsdoffscreen;

if(DirectDrawCreate(NULL, &lpdd, NULL) != DD_OK)
return FALSE;
if(lpdd->SetCooperativeLevel(GetActiveWindow(), DDSCL_EXCLUSIVE|DDSCL_FULLSCREEN) != DD_OK)
return FALSE;
if(lpdd->SetDisplayMode(800, 600, 32) != DD_OK)
return FALSE;

ZeroMemory( &ddsd, sizeof( ddsd ) );
ZeroMemory( &ddscaps, sizeof( ddscaps ) );
ZeroMemory( &ddsdoffscreen, sizeof(ddsdoffscreen));

ddsd.dwSize = sizeof(ddsd);
ddsd.dwFlags = DDSD_CAPS|DDSD_BACKBUFFERCOUNT;
ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE|DDSCAPS_FLIP|DDSCAPS_COMPLEX ;
ddsd.dwBackBufferCount = 1 ;
//创建主表面
if(lpdd->CreateSurface(&ddsd, &lpddsprimary, NULL) != DD_OK)
return FALSE;
//创建离屏表面
ddsdoffscreen.dwSize = sizeof(ddsdoffscreen);
ddsdoffscreen.dwFlags = DDSD_CAPS|DDSD_HEIGHT|DDSD_WIDTH;
ddsdoffscreen.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
ddsdoffscreen.dwWidth = 640;
ddsdoffscreen.dwHeight = 480;
if(lpdd->CreateSurface(&ddsdoffscreen, &lpddsoffscreen, NULL)!= DD_OK)
return FALSE;
//创建后表面
ddscaps.dwCaps = DDSCAPS_BACKBUFFER;

if(lpddsprimary->GetAttachedSurface(&ddscaps, &lpddsback) != DD_OK)
return FALSE;

return TRUE;

}

void FreeDDraw(void)
{
if(lpdd != NULL)
{
if(lpddsprimary != NULL)
{
lpddsprimary->Release();
lpddsprimary = NULL;
}

if(lpddsback != NULL)
{
lpddsback->Release();
lpddsback = NULL;
}
lpdd->Release();
lpdd = NULL;
}
}

void MainGame()
{
static int i = 0;
lpddpal = DDLoadPalette(lpdd, "mmm.bmp");


if(lpddpal)
lpddsback->SetPalette(lpddpal);
lpddsoffscreen = DDLoadBitmap(lpdd, "mmm.bmp", 0, 0);
rect.left = 0;
rect.top = 0;
rect.right = 300;
rect.bottom = 220;

lpddsback->BltFast(0, 0, lpddsoffscreen, &rect, DDBLTFAST_SRCCOLORKEY|DDBLTFAST_WAIT);


if(lpddsprimary->Flip(NULL, 0) != DD_OK )
{
FreeDDraw();
}


}
请大家帮帮忙！