C++ 按下关闭时：最小化到系统托盘并继续运行

Question

I have an app in c++ for windows, which should minimize the window of the command line when the user presses the close button. It shouldn't be in the taskbar anymore and have an icon in the system tray. What I mean is: when user presses close button, the program should only "hide" like i described.

I can only manage to make the program have an icon in the tray while running, but can't make it stay running when x is pressed

Thanks for help!

this is my code so far:

#include <iostream>
#include <Windows.h> // needed for console window and system tray functionality

// global variables
NOTIFYICONDATA trayIcon; // structure for the tray icon
HWND hwnd = GetConsoleWindow(); // handle to the console window

// function prototypes
void minimizeToTray(); // function to minimize the console window to the system tray

int main()
{
    // set up the tray icon
    trayIcon.cbSize = sizeof(NOTIFYICONDATA);
    trayIcon.hWnd = hwnd;
    trayIcon.uID = 1;
    trayIcon.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
    trayIcon.hIcon = (HICON)LoadImage(NULL, "icon.ico", IMAGE_ICON, 0, 0, LR_LOADFROMFILE); // specify the icon file
    trayIcon.uCallbackMessage = WM_USER + 1; // message identifier for tray icon clicks
    trayIcon.uVersion = NOTIFYICON_VERSION_4;
    strcpy_s(trayIcon.szTip, "Program Running");

    // add the tray icon to the system tray
    Shell_NotifyIcon(NIM_ADD, &trayIcon);

    std::cout << "Program running..." << std::endl;

    // set up a message loop to handle tray icon clicks and window messages
    MSG msg;
    while (true) // infinite loop
    {
        // check for messages
        while (PeekMessage(&msg, hwnd, 0, 0, PM_REMOVE))
        {
            // if the user clicks the close button, minimize the window to the tray
            if (msg.message == WM_CLOSE)
            {
                minimizeToTray();
                continue; // skip the rest of the message loop
            }

            // if the user clicks the tray icon, restore the window
            if (msg.message == WM_USER + 1)
            {
                ShowWindow(hwnd, SW_RESTORE);
            }

            // pass the message to the default window procedure
            DispatchMessage(&msg);
        }

        // do other tasks here
    }

    // remove the tray icon before exiting the program
    Shell_NotifyIcon(NIM_DELETE, &trayIcon);

    return 0;
}

// function to minimize the console window to the system tray
void minimizeToTray()
{
    // hide the console window
    ShowWindow(hwnd, SW_HIDE);

    // update the tray icon
    trayIcon.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
    Shell_NotifyIcon(NIM_MODIFY, &trayIcon);
}

When the user "closes" the window it should just hide and not close entirely, like ms teams or discord do

Answer 1

After testing your code, it definitely fails. It cannot get the message WM_CLOSE. Just as Hans Passant said, you can use SetConsoleCtrlHandler() to attached to the console receive the signal.

Here is my code. It runs well. It used ShellExecuteW() API to restart the program to implement minimization. Setting SW_MINIMIZE , it will minimize in the task bar. Setting SW_HIDE , it will minimize in the system tray. But it cannot be opened again.

#include <Windows.h> 
#include <string.h>     
#include <stdlib.h>     
#include <stdio.h>      
#include <errno.h>      
#include <iostream>


NOTIFYICONDATA trayIcon; 
HWND hwnd = GetConsoleWindow(); 

BOOL WINAPI ConsoleHandler(DWORD CEvent)
{
    char mesg[128];
    switch (CEvent)
    {

    case CTRL_C_EVENT:
        MessageBox(NULL,
            L"CTRL+C received!", L"CEvent", MB_OK);
        break;
    case CTRL_BREAK_EVENT:
        MessageBox(NULL,
            L"CTRL+BREAK received!", L"CEvent", MB_OK);
        break;
    case CTRL_CLOSE_EVENT:
      
        ShellExecuteW(NULL, L"open", L"yourexe.exe", NULL, NULL, SW_MINIMIZE);

        break;
    case CTRL_LOGOFF_EVENT:
        MessageBox(NULL,
            L"User is logging off!", L"CEvent", MB_OK);
        break;
    case CTRL_SHUTDOWN_EVENT:
        MessageBox(NULL,
            L"User is logging off!", L"CEvent", MB_OK);
        break;
    }
    return TRUE;
}

int main()
{

    trayIcon.cbSize = sizeof(NOTIFYICONDATA);
    trayIcon.hWnd = hwnd;
    trayIcon.uID = 1;
    trayIcon.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
    trayIcon.hIcon = (HICON)LoadImage(NULL, L"icon1.ico", IMAGE_ICON, 0, 0, LR_LOADFROMFILE); 
    trayIcon.uCallbackMessage = WM_USER + 1; 
    trayIcon.uVersion = NOTIFYICON_VERSION_4;
   
    Shell_NotifyIcon(NIM_ADD, &trayIcon);
    std::cout << "Program running..." << std::endl;
    
    MSG msg;
    if (SetConsoleCtrlHandler(
        (PHANDLER_ROUTINE)ConsoleHandler, TRUE) == FALSE)
    {
     
        printf("Unable to install handler!\n");
        return -1;
    }
    while (true) 
    {
        
        while (PeekMessage(&msg, hwnd, 0, 0, PM_REMOVE))
        {
           
            if (msg.message == WM_CLOSE)
            {          
                continue; 
            }
            
            if (msg.message == WM_USER + 1)
            {
                ShowWindow(hwnd, SW_RESTORE);
            }
            
            DispatchMessage(&msg);
        }       
       
    }
   
    Shell_NotifyIcon(NIM_DELETE, &trayIcon);
    return 0;
}