在我们开发Windows客户端程序时，往往会出现程序退出后，任务还保留之前程序的缓存图标。每打开关闭一次程序，图标会一直增加，导致托盘存放大量缓存图标。为了解决这个问题，我们可以通过下面的程序清理任务栏托盘图标缓存。

清理任务栏托盘缓存图标帮助类：

    public class TaskBarHelper
    {

        [DllImport("user32.dll", SetLastError = true)]
        static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);
        [DllImport("user32.dll")]
        static extern bool GetClientRect(IntPtr handle, out RECT rect);
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        static extern IntPtr SendMessage(IntPtr handle, UInt32 message, Int32 wParam, Int32 lParam);
        struct RECT
        {
            public int left, top, right, bottom;
        }

        public static void RefreshNotification()
        {
            var NotifyAreaHandle = GetNotifyAreaHandle();
            if (NotifyAreaHandle != IntPtr.Zero)
            {
                RefreshWindow(NotifyAreaHandle);
            }

            var NotifyOverHandle = GetNotifyOverHandle();
            if (NotifyOverHandle != IntPtr.Zero)
            {
                RefreshWindow(NotifyOverHandle);
            }
        }

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

        private static IntPtr GetNotifyAreaHandle()
        {
            var TrayWndHandle = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "Shell_TrayWnd", null);
            var TrayNotifyWndHandle = FindWindowEx(TrayWndHandle, IntPtr.Zero, "TrayNotifyWnd", null);
            var SysPagerHandle = FindWindowEx(TrayNotifyWndHandle, IntPtr.Zero, "SysPager", null);
            var NotifyAreaHandle = FindWindowEx(SysPagerHandle, IntPtr.Zero, "ToolbarWindow32", null);

            return NotifyAreaHandle;
        }

        private static IntPtr GetNotifyOverHandle()
        {
            var OverHandle = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "NotifyIconOverflowWindow", null);
            var NotifyOverHandle = FindWindowEx(OverHandle, IntPtr.Zero, "ToolbarWindow32", null);

            return NotifyOverHandle;
        }
    }

主程序启动时调用：

        public MainView()
        {
            InitializeComponent();
            TaskBarHelper.RefreshNotification();
        }