Timer.Dispose Method

Definition

Releases all resources used by the current instance of Timer.

Overloads

Dispose()

Releases all resources used by the current instance of Timer.

Dispose(WaitHandle)

Releases all resources used by the current instance of Timer and signals when the timer has been disposed of.

Dispose()

Source:
Timer.cs
Source:
Timer.cs
Source:
Timer.cs

Releases all resources used by the current instance of Timer.

C#
public void Dispose();

Implements

Examples

The following code example shows how to free the resources held by a Timer.

C#
using System;
using System.Threading;

class TimerExample
{
    static void Main()
    {
        // Create an AutoResetEvent to signal the timeout threshold in the
        // timer callback has been reached.
        var autoEvent = new AutoResetEvent(false);
        
        var statusChecker = new StatusChecker(10);

        // Create a timer that invokes CheckStatus after one second, 
        // and every 1/4 second thereafter.
        Console.WriteLine("{0:h:mm:ss.fff} Creating timer.\n", 
                          DateTime.Now);
        var stateTimer = new Timer(statusChecker.CheckStatus, 
                                   autoEvent, 1000, 250);

        // When autoEvent signals, change the period to every half second.
        autoEvent.WaitOne();
        stateTimer.Change(0, 500);
        Console.WriteLine("\nChanging period to .5 seconds.\n");

        // When autoEvent signals the second time, dispose of the timer.
        autoEvent.WaitOne();
        stateTimer.Dispose();
        Console.WriteLine("\nDestroying timer.");
    }
}

class StatusChecker
{
    private int invokeCount;
    private int  maxCount;

    public StatusChecker(int count)
    {
        invokeCount  = 0;
        maxCount = count;
    }

    // This method is called by the timer delegate.
    public void CheckStatus(Object stateInfo)
    {
        AutoResetEvent autoEvent = (AutoResetEvent)stateInfo;
        Console.WriteLine("{0} Checking status {1,2}.", 
            DateTime.Now.ToString("h:mm:ss.fff"), 
            (++invokeCount).ToString());

        if(invokeCount == maxCount)
        {
            // Reset the counter and signal the waiting thread.
            invokeCount = 0;
            autoEvent.Set();
        }
    }
}
// The example displays output like the following:
//       11:59:54.202 Creating timer.
//       
//       11:59:55.217 Checking status  1.
//       11:59:55.466 Checking status  2.
//       11:59:55.716 Checking status  3.
//       11:59:55.968 Checking status  4.
//       11:59:56.218 Checking status  5.
//       11:59:56.470 Checking status  6.
//       11:59:56.722 Checking status  7.
//       11:59:56.972 Checking status  8.
//       11:59:57.223 Checking status  9.
//       11:59:57.473 Checking status 10.
//       
//       Changing period to .5 seconds.
//       
//       11:59:57.474 Checking status  1.
//       11:59:57.976 Checking status  2.
//       11:59:58.476 Checking status  3.
//       11:59:58.977 Checking status  4.
//       11:59:59.477 Checking status  5.
//       11:59:59.977 Checking status  6.
//       12:00:00.478 Checking status  7.
//       12:00:00.980 Checking status  8.
//       12:00:01.481 Checking status  9.
//       12:00:01.981 Checking status 10.
//       
//       Destroying timer.

Remarks

Calling Dispose allows the resources used by the Timer to be reallocated for other purposes. For more information about Dispose, see Cleaning Up Unmanaged Resources.

Note

Callbacks can occur after the Dispose() method overload has been called, because the timer queues callbacks for execution by thread pool threads. You can use the Dispose(WaitHandle) method overload to wait until all callbacks have completed.

See also

Applies to

.NET 9 and other versions
Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.2, 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0

Dispose(WaitHandle)

Source:
Timer.cs
Source:
Timer.cs
Source:
Timer.cs

Releases all resources used by the current instance of Timer and signals when the timer has been disposed of.

C#
public bool Dispose(System.Threading.WaitHandle notifyObject);

Parameters

notifyObject
WaitHandle

The WaitHandle to be signaled when the Timer has been disposed of.

Returns

true if the function succeeds; otherwise, false.

Exceptions

The notifyObject parameter is null.

Remarks

Calling Dispose allows the resources used by the Timer to be reallocated for other purposes. For more information about Dispose, see Cleaning Up Unmanaged Resources.

When this method completes, it signals the WaitHandle specified by the notifyObject parameter.Use this overload of the Dispose method if you want to be able to block until you are certain that the timer has been disposed. The timer is not disposed until all currently queued callbacks have completed.

Note

If the callback uses the Change method to set the dueTime parameter to zero, a race condition can occur when the Dispose(WaitHandle) method overload is called: If the timer queues a new callback before the Dispose(WaitHandle) method overload detects that there are no callbacks queued, Dispose(WaitHandle) continues to block; otherwise, the timer is disposed while the new callback is being queued, and an ObjectDisposedException is thrown when the new callback calls the Change method.

See also

Applies to

.NET 9 and other versions
Product Versions
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1