创建一个基本的 Win32 窗口

#include <Windows.h>

//Forward declarations
bool InitMainWindow(HINSTANCE, int);
LRESULT CALLBACK MsgProc(HWND, UINT, WPARAM, LPARAM);

//Constants
const int WIDTH = 800;
const int HEIGHT = 600;

HWND hwnd = NULL;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    //Initialize the window
    if (!InitMainWindow(hInstance, nCmdShow))
    {
        return 1;
    }

    //Main message loop
    MSG msg = {0};
    while (WM_QUIT != msg.message)
    {
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return static_cast<int>(msg.wParam);
}

bool InitMainWindow(HINSTANCE hInstance, int nCmdShow)
{
    WNDCLASSEX wcex;
    wcex.cbSize = sizeof(wcex);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.lpfnWndProc = MsgProc;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wcex.lpszClassName = "Basic Win32 Window";
    wcex.lpszMenuName = NULL;
    wcex.hIconSm = LoadIcon(NULL, IDI_WINLOGO);

    //Register window class
    if (!RegisterClassEx(&wcex))
    {
        return false;
    }
    
    //Create window
    hwnd = CreateWindow(
        "Basic Win32 Window",
        "Win32 Window",
        WS_OVERLAPPED | WS_SYSMENU | WS_CAPTION,
        GetSystemMetrics(SM_CXSCREEN) / 2 - WIDTH / 2,
        GetSystemMetrics(SM_CYSCREEN) / 2 - HEIGHT / 2,
        WIDTH,
        HEIGHT,
        (HWND)NULL,
        (HMENU)NULL,
        hInstance,
        (LPVOID*)NULL);

    if (!hwnd)
    {
        return false;
    }

    ShowWindow(hwnd, nCmdShow);

    return true;
}

LRESULT CALLBACK MsgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;

    case WM_CHAR:
        switch (wParam)
        {
        case VK_ESCAPE:
            PostQuitMessage(0);
            return 0;
        }
        return 0;
    }

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