C++ event handling for click on notification area Icon Windows

Question

I want to achieve some kind of event handling for Windows. I have a program, that has a symbol in the Notification Area (System Tray) and I want the programm to show up again, when the user clicks on the Icon. Is there a simple Way to implement that in c++ as an Event? I have only found ways to this in C#.

It is a console Application and I want to change as few things as possible. But there is no WndProc handler for Console Application as far as I can tell.

Answer 1

Why no WndProc? Console application is a perfect win32 application, and it can use anything which non-console application can use.

Here's a simple, but a bit long example.

#include <windows.h>
#include <shellapi.h>

#include <iostream>
#include <cstring>

LRESULT CALLBACK WndProc(HWND hWnd, UINT iMsg, WPARAM wParam, LPARAM lParam);
BOOL WINAPI ConsoleRoutine(DWORD dwCtrlType);

LPCWSTR lpszClass = L"__hidden__";

int main()
{
    HINSTANCE hInstance = GetModuleHandle(nullptr);

    WNDCLASS wc;
    HWND hWnd;
    MSG msg;

    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hbrBackground = nullptr;
    wc.hCursor = nullptr;
    wc.hIcon = nullptr;
    wc.hInstance = hInstance;
    wc.lpfnWndProc = WndProc;
    wc.lpszClassName = lpszClass;
    wc.lpszMenuName = nullptr;
    wc.style = 0;
    RegisterClass(&wc);

    hWnd = CreateWindow(lpszClass, lpszClass, WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
        nullptr, nullptr, hInstance, nullptr);

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

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

LRESULT CALLBACK WndProc(HWND hWnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
    static NOTIFYICONDATA nid;

    switch (iMsg)
    {
        case WM_CREATE:
            std::memset(&nid, 0, sizeof(nid));
            nid.cbSize = sizeof(nid);
            nid.hWnd = hWnd;
            nid.uID = 0;
            nid.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
            nid.uCallbackMessage = WM_APP + 1;
            nid.hIcon = LoadIcon(nullptr, IDI_APPLICATION);
            lstrcpy(nid.szTip, L"con-notify");
            Shell_NotifyIcon(NIM_ADD, &nid);
            Shell_NotifyIcon(NIM_SETVERSION, &nid);
            return 0;
        case WM_APP + 1:
            switch (lParam)
            {
                case WM_LBUTTONDBLCLK:
                    std::cout << "notify dblclk" << std::endl;
                    break;
                case WM_RBUTTONDOWN:
                case WM_CONTEXTMENU:
                    break;
            }
            break;
        case WM_DESTROY:
            Shell_NotifyIcon(NIM_DELETE, &nid);
            MessageBox(nullptr, L"asdf", L"asdf", MB_OK);
            PostQuitMessage(0);
            return 0;
    }
    return DefWindowProc(hWnd,iMsg,wParam,lParam);
}

You probably want not to mess up your console program with message loop. If so, you can put notification code into another thread.