C# Signature:

[DllImport("kernel32.dll")]
static extern bool SetWaitableTimer(IntPtr hTimer, [In] ref long pDueTime,
   int lPeriod, TimerCompleteDelegate pfnCompletionRoutine,
   IntPtr lpArgToCompletionRoutine, bool fResume);

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

class WaitableTimer

{

    // Class that sets a WIN32 WaitableTimer. The timer will wake up the PC if the PC
    // is in standby or hibernation mode.
    class WaitableTimer
    {
        public delegate void TimerSetDelegate();
        public delegate void TimerCompleteDelegate();
    //
    public delegate void TimerSetDelegate();
    public delegate void TimerCompleteDelegate();

        public event TimerSetDelegate OnTimerSet;
        public event TimerCompleteDelegate OnTimerCompleted;
    public event TimerSetDelegate OnTimerSet;
    public event TimerCompleteDelegate OnTimerCompleted;

        [DllImport("kernel32.dll")]
        static extern IntPtr CreateWaitableTimer(IntPtr lpTimerAttributes, bool bManualReset, string lpTimerName);
    [DllImport("kernel32.dll")]
    static extern IntPtr CreateWaitableTimer(IntPtr lpTimerAttributes, bool bManualReset, string lpTimerName);

        [DllImport("kernel32.dll")]
        static extern bool SetWaitableTimer(IntPtr hTimer, [In] ref long ft, int lPeriod, TimerCompleteDelegate pfnCompletionRoutine, IntPtr  pArgToCompletionRoutine, bool fResume);
    [DllImport("kernel32.dll")]
    static extern bool SetWaitableTimer(IntPtr hTimer, [In] ref long ft, int lPeriod, TimerCompleteDelegate pfnCompletionRoutine, IntPtr  pArgToCompletionRoutine, bool fResume);

        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
        static extern Int32 WaitForSingleObject(IntPtr Handle, uint Wait);
    [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
    static extern Int32 WaitForSingleObject(IntPtr Handle, uint Wait);

        [DllImport("kernel32.dll")]
        static extern bool CancelWaitableTimer(IntPtr hTimer);
    [DllImport("kernel32.dll")]
    static extern bool CancelWaitableTimer(IntPtr hTimer);

        [DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool CloseHandle(IntPtr hObject);
    [DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Auto)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool CloseHandle(IntPtr hObject);

        private IntPtr handle;
        private uint INFINITE = 0xFFFFFFFF;
    private IntPtr handle;
    private uint INFINITE = 0xFFFFFFFF;

        public void SetTimer(long Interval)
        {
            // Creating the timer delegate
            //
            TimerCompleteDelegate TimerComplete = new TimerCompleteDelegate(TimerCompleted);
            TimerSetDelegate TimerSet = new TimerSetDelegate(TimerIsSet);
    public void SetTimer(long Interval)
    {
        // Creating the timer delegate
        //
        TimerCompleteDelegate TimerComplete = new TimerCompleteDelegate(TimerCompleted);
        TimerSetDelegate TimerSet = new TimerSetDelegate(TimerIsSet);

            // Creating the timer
            //
            Console.WriteLine("Creating WaitableTimer");
            handle = CreateWaitableTimer(IntPtr.Zero, true, "WaitableTimer");
            Console.WriteLine("Last Error = " + Marshal.GetLastWin32Error().ToString());
        // Creating the timer
        //
        Console.WriteLine("Creating WaitableTimer");
        handle = CreateWaitableTimer(IntPtr.Zero, true, "WaitableTimer");
        Console.WriteLine("Last Error = " + Marshal.GetLastWin32Error().ToString());

            // Setting up the timer, the long Interval value needs to be negative if
            // you want to set up a delay in milliseconds. ie
            // if Interval = -60000000 the timer will expire in 1 minute. Once expired it runs the
            // TimerComplete delegate
            //
            Console.WriteLine("Setting WaitableTimer");
            SetWaitableTimer(handle, ref Interval, 0, TimerComplete, IntPtr.Zero, true);
            Console.WriteLine("Last Error = " + Marshal.GetLastWin32Error().ToString()); // The error may be 1004 (Invalid flags), this is not critical
            Console.WriteLine("Timer set @ " + DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss"));
        // Setting up the timer, the long Interval value needs to be negative if
        // you want to set up a delay in milliseconds. ie
        // if Interval = -60000000 the timer will expire in 1 minute. Once expired it runs the
        // TimerComplete delegate
        //
        Console.WriteLine("Setting WaitableTimer");
        SetWaitableTimer(handle, ref Interval, 0, TimerComplete, IntPtr.Zero, true);
        Console.WriteLine("Last Error = " + Marshal.GetLastWin32Error().ToString()); // The error may be 1004 (Invalid flags), this is not critical
        Console.WriteLine("Timer set @ " + DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss"));

            // Starting a new thread which waits for the WaitableTimer to expire
            //
            Thread t_Wait = new Thread(new ThreadStart(WaitTimer));
            t_Wait.Start();
        // Starting a new thread which waits for the WaitableTimer to expire
        //
        Thread t_Wait = new Thread(new ThreadStart(WaitTimer));
        t_Wait.Start();

            // Raising Event Timer Set
            //
            if (OnTimerSet != null)
            {
                OnTimerSet();
            }
        }

        private void WaitTimer()
        // Raising Event Timer Set
        //
        if (OnTimerSet != null)
        {
            // Waiting for the timer to expire
            //
            if (WaitForSingleObject(handle, INFINITE) != 0)
            {
                Console.WriteLine("Last Error = " + Marshal.GetLastWin32Error().ToString());
            }
            else
            {
                Console.WriteLine("Timer expired @ " + DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss"));
            }

            // Closing the timer
            //
            CloseHandle(handle);

            // Raising event Timer Completed
            //
            if (OnTimerCompleted != null)
            {
                OnTimerCompleted();
            }
            OnTimerSet();
        }

        private void TimerCompleted()
        {
            // Routine executed once the timer has expired. This is executed independently of the
            // program calling this class implementation of the OnTimerCompleted Event
            //
            Console.WriteLine("Timer is complete in the class");
        }

        private void TimerIsSet()
        {
            Console.WriteLine("Timer is set in the class");
        }
    }

Alternative Managed API:

Do you know one? Please contribute it!

    private void WaitTimer()
    {
        // Waiting for the timer to expire
        //
        if (WaitForSingleObject(handle, INFINITE) != 0)
        {
            Console.WriteLine("Last Error = " + Marshal.GetLastWin32Error().ToString());
        }
        else
        {
            Console.WriteLine("Timer expired @ " + DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss"));
        }

        // Closing the timer
        //
        CloseHandle(handle);

        // Raising event Timer Completed
        //
        if (OnTimerCompleted != null)
        {
            OnTimerCompleted();
        }
    }

    private void TimerCompleted()
    {
        // Routine executed once the timer has expired. This is executed independently of the
        // program calling this class implementation of the OnTimerCompleted Event
        //
        Console.WriteLine("Timer is complete in the class");
    }

    private void TimerIsSet()
    {
        Console.WriteLine("Timer is set in the class");
    }

}

Alternative Managed API:

Do you know one? Please contribute it!

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