/*windows 开发所需头文件
包含Windows开发所需要的宏、类、函数、结构体等结构的定义*/
#include <windows.h>

HWND MainWindowHandle = 0;                                                              //主窗口句柄，相当于窗口的ID
bool InitWindowsApp(HINSTANCE instanceHandle, int show);            //初始化窗口函数
int Run();                                                                                                          //消息循环函数
LRESULT CALLBACK WndProc(HWND hWnd, UINT msg,               //消息处理函数
	WPARAM wParam, LPARAM lParam);

/*WinMain函数，相当于C++中的main函数，是程序运行的入口*/
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR pCmdLine, int nShowCmd)
{
    
    
	//初始化失败则弹出消息窗口提示
	if (!InitWindowsApp(hInstance, nShowCmd))
	{
    
    
		::MessageBox(0, L"Init - Failed", L"Error", MB_OK);
		return 0;
	}
	return Run();
}

//初始化窗口函数实现
bool InitWindowsApp(HINSTANCE instanceHandle, int show)
{
    
    
	//windows窗口类型的自定义
	WNDCLASS wc;
	wc.style = CS_HREDRAW | CS_VREDRAW;
	wc.lpfnWndProc = WndProc;
	wc.cbClsExtra = 0;
	wc.cbWndExtra = 0;
	wc.hInstance = instanceHandle;
	wc.hIcon = ::LoadIcon(0, IDI_APPLICATION);
	wc.hCursor = ::LoadCursor(0, IDC_ARROW);
	wc.hbrBackground = static_cast<HBRUSH>(::GetStockObject(WHITE_BRUSH));
	wc.lpszMenuName = 0;
	wc.lpszClassName = L"Hello";

	//向Windows系统注册窗口
	if (!::RegisterClass(&wc))
	{
    
    
		::MessageBox(0, L"RegisterClass - Failed", 0, 0);
		return false;
	}

	//根据自定义的窗口进行创建
	MainWindowHandle = ::CreateWindow(
		L"Hello",
		L"Hello",
		WS_OVERLAPPEDWINDOW,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		CW_USEDEFAULT,
		0,
		0,
		instanceHandle,
		0);

	//创建失败则弹出消息窗口提示
	if (MainWindowHandle == 0)
	{
    
    
		::MessageBox(0, L"CreateWindow - Failed", 0, 0);
		return false;
	}

	::ShowWindow(MainWindowHandle, show);           //显示窗口
	::UpdateWindow(MainWindowHandle);                   //进行窗口的刷新

	return true;
}

//消息循环函数定义
int Run()
{
    
    
	MSG msg;
	::ZeroMemory(&msg, sizeof(MSG));

	while (::GetMessage(&msg, 0, 0, 0))
	{
    
    
		::TranslateMessage(&msg);
		::DispatchMessage(&msg);
	}

	return msg.wParam;
}

//消息处理函数定义
LRESULT CALLBACK WndProc(HWND windowHandle, UINT msg, WPARAM wParam, LPARAM lParam)
{
    
    
	switch (msg)
	{
    
    
	case WM_LBUTTONDOWN:
		::MessageBox(0, L"Hello, Word", L"Hello", MB_OK);
		return 0;
	case WM_KEYDOWN:
		if (wParam == VK_ESCAPE)
		{
    
    
			::DestroyWindow(MainWindowHandle);
		}
		return 0;
	case WM_DESTROY:
		::PostQuitMessage(0);
		return 0;
	}
	return ::DefWindowProc(windowHandle, msg, wParam, lParam);
}