AnimateWindow调用背部景图片不显示

AnimateWindow调用后背景图片不显示
想要用AnimateWindow函数动态显示窗口，制造点炫酷的感觉，结果，炫倒是炫了，炫的不完美。背景图没显示啊白白的一个窗口。求解啊，各位大神。部分代码如下：

void Welcome()

{

	WNDCLASS welcome;

	HWND hwnd;

	MSG msg;


	welcome.cbClsExtra=0;

	welcome.cbWndExtra=0;

	welcome.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);

	welcome.hCursor=LoadCursor(bground,MAKEINTRESOURCE(IDC_CURSOR1));

	welcome.hIcon=LoadIcon(NULL,IDI_APPLICATION);

	welcome.hInstance=program;

	welcome.lpfnWndProc=WelcomeProc;

	welcome.lpszClassName=L"Welcome";

	welcome.lpszMenuName=0;

	welcome.style=CS_HREDRAW|CS_VREDRAW;


	RegisterClass(&welcome);

	hwnd=CreateWindow(L"Welcome",L"Welcome",WS_POPUP,0,0,320,480,NULL,NULL,program,NULL);	

	AnimateWindow(hwnd,2000,AW_CENTER);

	UpdateWindow(hwnd);

	while(GetMessage(&msg,NULL,NULL,NULL))

	{

		if(welcome_flag==0)

			break;

		TranslateMessage(&msg);

		DispatchMessage(&msg);

	}

}

LRESULT CALLBACK WelcomeProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)

{

	HDC hdc;

	HDC hdc_paint;

	HBITMAP bitmap;

	PAINTSTRUCT ps;


	switch(msg)

	{

	case WM_PAINT:

		BeginPaint(hwnd,&ps);

		hdc=GetDC(hwnd);

		hdc_paint=CreateCompatibleDC(hdc);

		bitmap=LoadBitmap(bground,MAKEINTRESOURCE(IDB_BITMAP4));

		SelectObject(hdc_paint,bitmap);

		BitBlt(hdc,0,0,320,480,hdc_paint,0,0,SRCCOPY);

		DeleteDC(hdc_paint);

		DeleteDC(hdc);

		EndPaint(hwnd,&ps);

		return 0;

	case WM_RBUTTONDOWN:

		DestroyWindow(hwnd);

		welcome_flag=0;

		return 0;

	}

	return DefWindowProc(hwnd,msg,wParam,lParam);

}

------解决方案--------------------
 DeleteDC(hdc); 
getdc 不用deletedc删除！
------解决方案--------------------
法1：
在AnimateWindow后面增加InvalidateRect

    AnimateWindow(hwnd,2000,AW_CENTER);

    UpdateWindow(hwnd); // 这个不起作用啊

    InvalidateRect(hWnd, NULL, FALSE);

法2：增加消息WM_PRINTCLIENT处理

case WM_PRINTCLIENT:

        hdc=(HDC)wParam;

        hdc_paint=CreateCompatibleDC(hdc);

        bitmap=LoadBitmap(bground,MAKEINTRESOURCE(IDB_BITMAP4));

        HBITMAP bm=(HBITMAP)SelectObject(hdc_paint,bitmap);

	BitBlt(hdc,0,0,320,480,hdc_paint,0,0,SRCCOPY);

	SelectObject(hdc_paint,bm); //

	DeleteObject(bitmap); // 漏了这个释放

        DeleteDC(hdc_paint);

        return 0;

------解决方案--------------------

引用:

法1：
在AnimateWindow后面增加InvalidateRect

    AnimateWindow(hwnd,2000,AW_CENTER);

    UpdateWindow(hwnd); // 这个不起作用啊

    InvalidateRect(hWnd, NULL, FALSE);

法2：增加消息WM_PRINTCLIENT处理

case WM_PRINTCLIENT:

        hdc=(HDC)wParam;

        hdc_paint=CreateCompatibleDC(hdc);

        bitmap=LoadBitmap(bground,MAKEINTRESOURCE(IDB_BITMAP4));