win32 CreateWindow 宽度错误

[wl_tian_dao_chou_qin]

hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
0, 0, 1280, 720, NULL, NULL, hInstance, NULL);

创建窗口时写了1280*720 ,实际上在接收
case WM_SIZE:
{
float aa = LOWORD(lParam); 这个 aa = 1265
float bb = HIWORD(lParam); 这个bb == 675
break;
}
根本不是自己想的，这样会出问题，实际创建的小于我想要的。如何解决

[信阳毛尖]

那是因为你创建的是WS_OVERLAPPEDWINDOW风格带边框和标题栏的窗口啊 这种情况下，WM_SIZE消息中的cx和cy只是客户区的宽度和高度，你可以进行下面两项测试，分别看看rtWindow和rtClient里面的相关值： 测试一：

 hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
   0, 0, 1280, 720, NULL, NULL, hInstance, NULL);

//*********************************************************************
DWORD aa(0),bb(0);
RECT rtWindow = {0},rtClient={0};

//......
//......
	case WM_SIZE:
		aa = LOWORD(lParam);
		bb = HIWORD(lParam);
		::GetWindowRect(hWnd,&rtWindow);
		::GetClientRect(hWnd,&rtClient);
		return DefWindowProc(hWnd, message, wParam, lParam);
//.....
//....

测试二：

 hWnd = CreateWindow(szWindowClass, szTitle, WS_CLIPCHILDREN|WS_CLIPSIBLINGS|WS_POPUP,
   0, 0, 1280, 720, NULL, NULL, hInstance, NULL);

//*********************************************************************
DWORD aa(0),bb(0);
RECT rtWindow = {0},rtClient={0};

//......
//......
	case WM_SIZE:
		aa = LOWORD(lParam);
		bb = HIWORD(lParam);
		::GetWindowRect(hWnd,&rtWindow);
		::GetClientRect(hWnd,&rtClient);
		return DefWindowProc(hWnd, message, wParam, lParam);
//.....
//....