主窗口,子窗口,拥有窗口关闭消息顺序

参考自:

https://baijiahao.baidu.com/s?id=1751789480271344172

1 先说结论, 主窗口执行 DestroyWindow函数, 拥有窗口跟子窗口以及主窗口收到 WM_DESTROY, WM_NCDESTROY的顺序是有区别, 顺序如下:

main WM_CLOSE
owned WM_DESTROY
owned WM_NCDESTROY
main WM_DESTROY
sub WM_DESTROY
sub WM_NCDESTROY
main WM_NCDESTROY

2 验证核心代码如下, 在程序运行时, 点击主窗口的关闭按钮

#include "stdafx.h"
#include "msgTest.h"

#define MAX_LOADSTRING 100
#define SUB_WIN_CLASS L"subWinClass"
#define SUB_WIN_NAME L"subWinName"

#define OWNED_WIN_CLASS L"ownedWinClass"
#define OWNED_WIN_NAME L"ownedWinName"

// 全局变量: 
HINSTANCE hInst = NULL; // 当前实例
WCHAR szTitle[MAX_LOADSTRING]; // 标题栏文本
WCHAR szWindowClass[MAX_LOADSTRING];// 主窗口类名

HWND gHMainWnd = NULL; //主窗口句柄
HWND gSubWnd = NULL; // 子窗口句柄
HWND gOwnedWnd = NULL; // 拥有的窗口

// 此代码模块中包含的函数的前向声明: 
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);

LRESULT CALLBACK WndProcSub(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CLOSE:
        OutputDebugStringW(L"sub WM_CLOSE\n");
        DestroyWindow(hWnd);
        break;
    case WM_DESTROY:
        OutputDebugStringW(L"sub WM_DESTROY\n");
        break;
    case WM_NCDESTROY:
        OutputDebugStringW(L"sub WM_NCDESTROY\n");
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    };

    return 0;
}

bool CreateSubWnd(HINSTANCE hInstance, int nCmdShow)
{
    WNDCLASSEXW wcex;
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_MSGTEST));
    wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = SUB_WIN_CLASS;
    wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    if (!RegisterClassExW(&wcex))
        return false;

    gSubWnd = CreateWindowExW(WS_EX_CLIENTEDGE,SUB_WIN_CLASS, SUB_WIN_NAME, WS_CHILDWINDOW, 10, 10, 100, 100, gHMainWnd, nullptr, hInstance, nullptr);
    if (!gSubWnd)
        return false;

    ShowWindow(gSubWnd, nCmdShow);
    UpdateWindow(gSubWnd);

    return true;
}

LRESULT CALLBACK WndProcOwned(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CLOSE:
        OutputDebugStringW(L"owned WM_CLOSE\n");
        DestroyWindow(hWnd);
        break;
    case WM_DESTROY:
        OutputDebugStringW(L"owned WM_DESTROY\n");
        break;
    case WM_NCDESTROY:
        OutputDebugStringW(L"owned WM_NCDESTROY\n");
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    };

    return 0;
}

bool CreateOwnedWnd(HINSTANCE hInstance, int nCmdShow)
{
    WNDCLASSEXW wcex;
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_MSGTEST));
    wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = OWNED_WIN_CLASS;
    wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    if (!RegisterClassExW(&wcex))
        return false;

    gOwnedWnd = CreateWindowExW(0, OWNED_WIN_CLASS, OWNED_WIN_NAME, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 400, 200, gHMainWnd, nullptr, hInstance, nullptr);
    if (!gOwnedWnd)
        return false;

    ShowWindow(gOwnedWnd, nCmdShow);
    UpdateWindow(gOwnedWnd);

    return true;
}

int APIENTRY wWinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPWSTR lpCmdLine,int nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: 在此放置代码。

    // 初始化全局字符串
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_MSGTEST, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // 执行应用程序初始化: 
    if (!InitInstance(hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_MSGTEST));

    // 主消息循环: 
    MSG msg;
    while (GetMessageW(&msg, NULL, 0, 0))
    {
        //if (!TranslateAcceleratorW(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessageW(&msg);
        }
    }

    return (int) msg.wParam;
}

ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_MSGTEST));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_MSGTEST);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}

BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // 将实例句柄存储在全局变量中

   gHMainWnd = CreateWindowExW(0,szWindowClass, szTitle, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, 400, 200, nullptr, nullptr, hInstance, nullptr);
   if (!gHMainWnd)
   {
      return FALSE;
   }

   CreateSubWnd(hInstance, nCmdShow);
   CreateOwnedWnd(hInstance, nCmdShow);

   ShowWindow(gHMainWnd, nCmdShow);
   UpdateWindow(gHMainWnd);

   return TRUE;
}


LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    if (hWnd == gSubWnd)
        return WndProcSub(hWnd, message, wParam, lParam);
    else if (hWnd == gOwnedWnd)
        return WndProcOwned(hWnd, message, wParam, lParam);

    switch (message)
    {
    case WM_CREATE:
        break;
    case WM_COMMAND:
    {
        int wmId = LOWORD(wParam);
        // 分析菜单选择: 
        switch (wmId)
        {
        case IDM_ABOUT:
            DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
            break;
        case IDM_EXIT:
            DestroyWindow(hWnd);
            break;
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
        }
    }
    break;
    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hWnd, &ps);
        // TODO: 在此处添加使用 hdc 的任何绘图代码...
        EndPaint(hWnd, &ps);
    }
    break;
    case WM_CLOSE:
        OutputDebugStringW(L"main WM_CLOSE\n");
        DestroyWindow(hWnd);
        break;
    case WM_DESTROY:
        //PostQuitMessage(0);
        OutputDebugStringW(L"main WM_DESTROY\n");
        break;
    case WM_NCDESTROY:
        PostQuitMessage(0);
        OutputDebugStringW(L"main WM_NCDESTROY\n");
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// “关于”框的消息处理程序。
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    switch (message)
    {
    case WM_INITDIALOG:
        return (INT_PTR)TRUE;

    case WM_COMMAND:
        if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
        {
            EndDialog(hDlg, LOWORD(wParam));
            return (INT_PTR)TRUE;
        }
        break;
    }
    return (INT_PTR)FALSE;
}