NativeMethods.cs

#region Using statements

using System;
using System.Runtime.InteropServices;

#endregion Using statements

namespace WeekNumber
{
    internal static class NativeMethods
    {
        #region Internal constants

        internal const int HWND_BROADCAST = 0xffff;
        internal const int WM_SETTINGCHANGE = 0x001a;

        #endregion Internal constants

        #region External user32.dll function to free GDI+ icon from memory

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        internal static extern bool DestroyIcon(IntPtr handle);

        #endregion External user32.dll function to free GDI+ icon from memory

        #region External user32.dll function to inform Windows about changed taskbar setting

        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        internal static extern bool SendNotifyMessage(IntPtr hWnd, uint Msg, UIntPtr wParam, string lParam);

        #endregion External user32.dll function to inform Windows about changed taskbar setting

        #region External wininet.dll function to check Internet connection state

        [DllImport("wininet.dll", CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private extern static bool InternetGetConnectedState(out int Description, int ReservedValue);

        internal static bool IsConnectedToInternet()
        {
            return InternetGetConnectedState(out _, 0);
        }

        #endregion External wininet.dll function to check Internet connection state

        #region Refresh tray area (only English user interface)

        [StructLayout(LayoutKind.Sequential)]
        public struct RECT
        {
            public int left;
            public int top;
            public int right;
            public int bottom;
        }

        [DllImport("user32.dll")]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll")]
        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass,
            string lpszWindow);

        [DllImport("user32.dll")]
        public static extern bool GetClientRect(IntPtr hWnd, out RECT lpRect);

        [DllImport("user32.dll")]
        public static extern IntPtr SendMessage(IntPtr hWnd, uint msg, int wParam, int lParam);

        public static void RefreshTrayArea()
        {
            Log.LogCaller();
            IntPtr systemTrayContainerHandle = FindWindow("Shell_TrayWnd", null);
            IntPtr systemTrayHandle = FindWindowEx(systemTrayContainerHandle, IntPtr.Zero, "TrayNotifyWnd", null);
            IntPtr sysPagerHandle = FindWindowEx(systemTrayHandle, IntPtr.Zero, "SysPager", null);
            IntPtr notificationAreaHandle = FindWindowEx(sysPagerHandle, IntPtr.Zero, "ToolbarWindow32", "Notification Area");
            if (notificationAreaHandle == IntPtr.Zero)
            {
                notificationAreaHandle = FindWindowEx(sysPagerHandle, IntPtr.Zero, "ToolbarWindow32",
                    "User Promoted Notification Area");
                IntPtr notifyIconOverflowWindowHandle = FindWindow("NotifyIconOverflowWindow", null);
                IntPtr overflowNotificationAreaHandle = FindWindowEx(notifyIconOverflowWindowHandle, IntPtr.Zero,
                    "ToolbarWindow32", "Overflow Notification Area");
                RefreshTrayArea(overflowNotificationAreaHandle);
            }
            RefreshTrayArea(notificationAreaHandle);
        }

        private static void RefreshTrayArea(IntPtr windowHandle)
        {
            const uint wmMousemove = 0x0200;
            GetClientRect(windowHandle, out RECT rect);
            for (var x = 0; x < rect.right; x += 5)
                for (var y = 0; y < rect.bottom; y += 5)
                    SendMessage(windowHandle, wmMousemove, 0, (y << 16) + x);
        }

        #endregion Refresh tray area (only English user interface)
    }
}