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Timer Class

Implements a timer that raises an event at user-defined intervals. This timer is optimized for use in Windows Forms applications and must be used in a window.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public class Timer : Component
public class Timer extends Component
public class Timer extends Component
Not applicable.

A Timer is used to raise an event at user-defined intervals. This Windows timer is designed for a single-threaded environment where UI threads are used to perform processing. It requires that the user code have a UI message pump available and always operate from the same thread, or marshal the call onto another thread.

When you use this timer, use the Tick event to perform a polling operation or to display a splash screen for a specified period of time. Whenever the Enabled property is set to true and the Interval property is greater than zero, the Tick event is raised at intervals based on the Interval property setting.

This class provides methods to set the interval, and to start and stop the timer.

NoteNote:

The Windows Forms Timer component is single-threaded, and is limited to an accuracy of 55 milliseconds. If you require a multithreaded timer with greater accuracy, use the Timer class in the System.Timers namespace.

The following example implements a simple interval timer, which sets off an alarm every five seconds. When the alarm occurs, a MessageBox displays a count of the number of times the alarm has started and prompts the user as to whether the timer should continue to run.

public class Class1 {
    static System.Windows.Forms.Timer myTimer = new System.Windows.Forms.Timer();
    static int alarmCounter = 1;
    static bool exitFlag = false;
 
    // This is the method to run when the timer is raised.
    private static void TimerEventProcessor(Object myObject,
                                            EventArgs myEventArgs) {
       myTimer.Stop();
 
       // Displays a message box asking whether to continue running the timer.
       if(MessageBox.Show("Continue running?", "Count is: " + alarmCounter, 
          MessageBoxButtons.YesNo) == DialogResult.Yes) {
          // Restarts the timer and increments the counter.
          alarmCounter +=1;
          myTimer.Enabled = true;
       }
       else {
          // Stops the timer.
          exitFlag = true;
       }
    }
 
    public static int Main() {
       /* Adds the event and the event handler for the method that will 
          process the timer event to the timer. */
       myTimer.Tick += new EventHandler(TimerEventProcessor);
 
       // Sets the timer interval to 5 seconds.
       myTimer.Interval = 5000;
       myTimer.Start();
 
       // Runs the timer, and raises the event.
       while(exitFlag == false) {
          // Processes all the events in the queue.
          Application.DoEvents();
       }
    return 0;
    }
 }
    

public class Class1
{
    private static System.Windows.Forms.Timer myTimer = 
        new System.Windows.Forms.Timer();
    private static int alarmCounter = 1;
    private static boolean exitFlag = false;

    // This is the method to run when the timer is raised.
    private static void TimerEventProcessor(Object myObject, 
                                            EventArgs myEventArgs)
    {
        myTimer.Stop();

        // Displays a message box asking whether to continue running the timer.
        if (MessageBox.Show("Continue running?", "Count is: " 
            + alarmCounter, MessageBoxButtons.YesNo).Equals(DialogResult.Yes)) {
            // Restarts the timer and increments the counter.
            alarmCounter += 1;
            myTimer.set_Enabled(true);
        }
        else {
            // Stops the timer.
            exitFlag = true;
        }
    } //TimerEventProcessor

    public static void main(String[] args)
    {
        /* Adds the event and the event handler for the method that will 
           process the timer event to the timer. 
         */
        myTimer.add_Tick(new EventHandler(TimerEventProcessor));

        // Sets the timer interval to 5 seconds.
        myTimer.set_Interval(5000);
        myTimer.Start();

        // Runs the timer, and raises the event.
        while (exitFlag == false) {
            // Processes all the events in the queue.
            Application.DoEvents();
        }
        return;
    } //main
} //Class1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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