Timer.Tick Evento

Definição

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Ocorre quando o intervalo especificado tiver terminado e o temporizador estiver habilitado.

public:
 event EventHandler ^ Tick;

public event EventHandler Tick;

member this.Tick : EventHandler 

Public Custom Event Tick As EventHandler 

Tipo de evento

EventHandler

Exemplos

O exemplo de código a seguir implementa um temporizador de intervalo simples, que dispara um alarme a cada cinco segundos. Quando o alarme ocorre, um MessageBox exibe uma contagem do número de vezes que o alarme foi iniciado e solicita ao usuário se o temporizador deve continuar a ser executado.

public ref class Class1
{
private:
   static System::Windows::Forms::Timer^ myTimer = gcnew System::Windows::Forms::Timer;
   static int alarmCounter = 1;
   static bool exitFlag = false;

   // This is the method to run when the timer is raised.
   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?", String::Format( "Count is: {0}", 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 void Main()
   {
      
      /* Adds the event and the event handler for the method that will 
                process the timer event to the timer. */
      myTimer->Tick += gcnew 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();
      }
   }

};

int main()
{
   Class1::Main();
}

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 Shared WithEvents myTimer As New System.Windows.Forms.Timer()
    Private Shared alarmCounter As Integer = 1
    Private Shared exitFlag As Boolean = False    
    
    ' This is the method to run when the timer is raised.
    Private Shared Sub TimerEventProcessor(myObject As Object, _
                                           ByVal myEventArgs As EventArgs) _
                                       Handles myTimer.Tick
        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 Then
            ' Restarts the timer and increments the counter.
            alarmCounter += 1
            myTimer.Enabled = True
        Else
            ' Stops the timer.
            exitFlag = True
        End If
    End Sub
    
    Public Shared Sub Main()
        ' Adds the event and the event handler for the method that will
        ' process the timer event to the timer.
        
        ' 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()
        End While

    End Sub    

End Class

Comentários

Chamar o Assert método na Debug classe de dentro do evento pode não se comportar conforme o Tick esperado, pois exibir a caixa de diálogo de asserção pode fazer com que o Windows acione o Tick evento repetidamente. Recomendamos que você se abstiver de testar as declarações dentro desse evento e use os Writemétodos , WriteIf, WriteLineou WriteLineIf em vez disso.

Para obter mais informações sobre como lidar com eventos, consulte Manipulando e levantando eventos.