C++创建一个窗口

#include<Windows.h>

LRESULT CALLBACK GLWindowProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
	switch (msg)
	{
	case WM_CLOSE:
		PostQuitMessage(0);
		return 0;
	default:
		break;
	}
	return DefWindowProc(hwnd,msg,wParam,lParam);
}

INT WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPreInstance,LPSTR lpCmdLine,int nShowCmd)
{
	WNDCLASSEX wndclass;
	wndclass.cbClsExtra = 0;
	wndclass.cbSize = sizeof(WNDCLASSEX);
	wndclass.cbWndExtra = 0;
	wndclass.hbrBackground = NULL;
	wndclass.hCursor = LoadCursor(NULL,IDC_ARROW);
	wndclass.hIcon = NULL;
	wndclass.hIconSm = NULL;
	wndclass.hInstance = hInstance;
	wndclass.lpfnWndProc = GLWindowProc;
	wndclass.lpszClassName = L"GLWindow";
	wndclass.lpszMenuName = NULL;
	wndclass.style = CS_VREDRAW | CS_HREDRAW;
	ATOM atom = RegisterClassEx(&wndclass);
	if (!atom)
	{
		MessageBox(NULL,L"Notice",L"Error",MB_OK);
		return 0;
	}

	RECT rect;
	rect.left = 0;
	rect.right = 800;
	rect.top = 0;
	rect.bottom = 600;
	AdjustWindowRect(&rect,WS_OVERLAPPEDWINDOW,NULL);
	int windowWidth = rect.right - rect.left;
	int windowHeight = rect.bottom - rect.top;

	//创建窗口
	HWND hwnd = CreateWindowEx(NULL, L"GLWindow", L"OpwnGL Window", WS_OVERLAPPEDWINDOW, 100, 100, windowWidth, windowHeight, NULL, NULL, hInstance, NULL);

	//显示窗口
	ShowWindow(hwnd,SW_SHOW);
	UpdateWindow(hwnd);

	//程序持续运行
	MSG msg;
	while (true)
	{
		if (PeekMessage(&msg, NULL, NULL, NULL, PM_REMOVE))
		{
			if (msg.message == WM_QUIT)
				break;
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}
	return 0;
}