#include <windows.h>

#define WIN_WIDTH  500
#define WIN_HEIGHT 500

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

int WINAPI WinMain(
	HINSTANCE	hInstance,
	HINSTANCE	hPrevInstance,
	LPSTR		lpCmdLine,
	int			nShowCmd)
{
	static TCHAR lpszAppName[] = TEXT("Hello World");
	HWND      hwnd;
	MSG       msg;
	WNDCLASS  wc;

	wc.style = CS_HREDRAW | CS_VREDRAW;
	wc.lpfnWndProc = WndProc;
	wc.cbClsExtra = 0;
	wc.cbWndExtra = 0;
	wc.hInstance = hInstance;
	wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
	wc.hCursor = LoadCursor(NULL, IDC_ARROW);
	wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
	wc.lpszMenuName = NULL;
	wc.lpszClassName = lpszAppName;

	// 注册窗口类
	if (!RegisterClass(&wc))
	{
		MessageBox(NULL, TEXT("RegisterCalss Failed!"),
			lpszAppName, MB_ICONERROR);
		return 0;
	}

	// 创建应用程序主窗口
	hwnd = CreateWindow(lpszAppName,
		TEXT("Hello World Program"),
		WS_OVERLAPPEDWINDOW,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		WIN_WIDTH,
		WIN_HEIGHT,
		NULL,
		NULL,
		hInstance,
		NULL);

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

	// 消息循环
	while (GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	return (int)msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	HDC         hdc;
	PAINTSTRUCT ps;
	RECT        rect;

	switch (message)
	{
	case WM_CREATE:
		return 0;
	case WM_PAINT:
		hdc = BeginPaint(hwnd, &ps);
		GetClientRect(hwnd, &rect);
		DrawText(hdc, TEXT("Hello World!"), -1, &rect,
			DT_SINGLELINE | DT_CENTER | DT_VCENTER);
		EndPaint(hwnd, &ps);
		return 0;
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}

	return DefWindowProc(hwnd, message, wParam, lParam);
}