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How to: Run Procedures at Set Intervals with the Windows Forms Timer Component

Updated: July 2009

You might sometimes want to create a procedure that runs at specific time intervals until a loop has finished or that runs when a set time interval has elapsed. The Timer component makes such a procedure possible.

This component is designed for a Windows Forms environment. If you need a timer that is suitable for a server environment, see Introduction to Server-Based Timers.

NoteNote:

There are some limitations when using the Timer component. For more information, see Limitations of the Windows Forms Timer Component's Interval Property.

To run a procedure at set intervals with the Timer component

  1. Add a Timer to your form. See the following Example section for an illustration of how to do this programmatically. Visual Studio also has support for adding components to a form. How to: Add Controls Without a User Interface to Windows Forms
    How to: Add Controls Without a User Interface to Windows Forms
    How to: Add Controls Without a User Interface to Windows Forms
    How to: Add Controls Without a User Interface to Windows Forms

  2. Set the Interval property (in milliseconds) for the timer. This property determines how much time will pass before the procedure is run again.

    NoteNote:

    The more often a timer event occurs, the more processor time is used in responding to the event. This can slow down overall performance. Do not set a smaller interval than you need.

  3. Write appropriate code in the Tick event handler. The code you write in this event will run at the interval specified in the Interval property.

  4. Set the Enabled property to true to start the timer. The Tick event will begin to occur, running your procedure at the set interval.

  5. At the appropriate time, set the Enabled property to false to stop the procedure from running again. Setting the interval to 0 does not cause the timer to stop.

This first code example tracks the time of day in one-second increments. It uses a Button, a Label, and a Timer component on a form. The Interval property is set to 1000 (equal to one second). In the Tick event, the label's caption is set to the current time. When the button is clicked, the Enabled property is set to false, stopping the timer from updating the label's caption. The following code example requires that you have a form with a Button control named Button1, a Timer control named Timer1, and a Label control named Label1.

private void InitializeTimer()
{
    // Call this procedure when the application starts.
    // Set to 1 second.
    Timer1.Interval = 1000;
    Timer1.Tick += new EventHandler(Timer1_Tick);

    // Enable timer.
    Timer1.Enabled = true;

    Button1.Text = "Stop";
    Button1.Click += new EventHandler(Button1_Click);
}

private void Timer1_Tick(object Sender, EventArgs e)   
{
   // Set the caption to the current time.
   Label1.Text = DateTime.Now.ToString();
}

private void Button1_Click(object sender, EventArgs e)
{
  if ( Button1.Text == "Stop" )
  {
    Button1.Text = "Start";
    Timer1.Enabled = false;
  }
  else
  {
    Button1.Text = "Stop";
    Timer1.Enabled = true;
  }
}

This second code example runs a procedure every 600 milliseconds until a loop has finished. The following code example requires that you have a form with a Timer control named Timer1 and a Label control named Label1.

// This variable will be the loop counter.
private int counter;

private void InitializeTimer()
{
   // Run this procedure in an appropriate event.
   counter = 0;
   timer1.Interval = 600;
   timer1.Enabled = true;
   // Hook up timer's tick event handler.
   this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
}

private void timer1_Tick(object sender, System.EventArgs e)   
{
   if (counter >= 10) 
   {
      // Exit loop code.
      timer1.Enabled = false;
      counter = 0;
   }
   else
   {
      // Run your procedure here.
      // Increment counter.
      counter = counter + 1;
      label1.Text = "Procedures Run: " + counter.ToString();
      }
}

Date

History

Reason

July 2009

Fixed first example.

Customer feedback.

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