Tray Notifications

This section covers functions related to managing notifications in the system tray area of the Windows user interface. These functions allow applications to display icons, tooltips, and notifications to users, often used for status updates or alerts.

Related Functions

                Note: Proper handling of tray notifications involves creating a hidden window to receive messages from the system. The Shell_NotifyIcon function is the primary interface for adding, modifying, or removing tray icons and associated notifications.
            

Key Concepts

System Tray Icons

Applications can display an icon in the notification area (system tray) to provide a visual presence and a way for users to interact with the application. This is typically done using the NIM_ADD flag with Shell_NotifyIcon.

Notification Balloons

Modern Windows versions support notification balloons (or pop-ups) that appear near the system tray icon. These balloons can display text, titles, and icons, and can be dismissed automatically or by user interaction. The NIIF_INFO, NIIF_WARNING, and NIIF_ERROR flags for the uVersion parameter in Shell_NotifyIcon control the balloon's appearance.

User Interaction

Applications need to handle mouse events (like clicks or hovers) on their tray icon to provide context menus or respond to user actions. This is achieved by specifying a window handle and message identifiers when adding the icon via Shell_NotifyIcon.

Example Usage Snippet (Conceptual)


// Include necessary headers
#include <windows.h>
#include <shellapi.h>

// Define a unique message for tray icon notifications
#define WM_MY_TRAY_NOTIFICATION (WM_USER + 1)

// ... in your application's initialization ...

    NOTIFYICONDATA nid;
    ZeroMemory(&nid, sizeof(nid));

    nid.cbSize = sizeof(nid);
    nid.hWnd = your_window_handle; // Handle to your application's window
    nid.uID = 1;                   // Unique identifier for the icon
    nid.uFlags = NIF_ICON | NIF_TIP;
    nid.hIcon = LoadIcon(GetModuleHandle(NULL), MAKEINTRESOURCE(IDI_MYAPPICON)); // Your application's icon resource
    wcscpy_s(nid.szTip, L"My Application"); // Tooltip text

    // Add the icon to the system tray
    Shell_NotifyIcon(NIM_ADD, &nid);

// ... in your window's message loop ...

    case WM_MY_TRAY_NOTIFICATION:
        switch (LOWORD(lParam))
        {
            case WM_LBUTTONUP: // Left mouse button released
                // Show application's main window or context menu
                break;
            case WM_RBUTTONUP: // Right mouse button released
                // Show context menu for the tray icon
                break;
            // Handle other notification codes (e.g., balloon clicks)
        }
        break;

// ... in your application's cleanup ...

    nid.uFlags = 0; // Clear flags to signal removal
    Shell_NotifyIcon(NIM_DELETE, &nid);

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