TrackBar.ValueChanged TrackBar.ValueChanged TrackBar.ValueChanged TrackBar.ValueChanged Event

Définition

Se produit lorsque la propriété Value sur une barre de suivi change, suite à un mouvement de la case de défilement ou à une manipulation dans le code.Occurs when the Value property of a track bar changes, either by movement of the scroll box or by manipulation in code.

public:
 event EventHandler ^ ValueChanged;
public event EventHandler ValueChanged;
member this.ValueChanged : EventHandler 
Public Custom Event ValueChanged As EventHandler 

Exemples

L’exemple de code suivant montre comment utiliser les TickStylemembres Minimum, et Maximum et comment gérer l' ValueChanged événement.The following code example demonstrates how to use the TickStyle, Minimum, and Maximum members and how to handle the ValueChanged event. Pour exécuter l’exemple, collez le code suivant dans un formulaire qui contient TrackBar un nom TrackBar1 de contrôle TextBox et un TextBox1contrôle nommé.To run the example, paste the following code into a form that contains a TrackBar control name TrackBar1 and a TextBox control named TextBox1. Appelez la InitializeTrackBar méthode à partir du constructeur du formulaire Load ou de la méthode de gestion d’événements.Call the InitializeTrackBar method from the form's constructor or Load event-handling method.

   //Declare a new TrackBar object.
internal:
   System::Windows::Forms::TrackBar^ TrackBar1;

   // Initalize the TrackBar and add it to the form.
private:
   void InitializeTrackBar()
   {
      this->TrackBar1 = gcnew System::Windows::Forms::TrackBar;
      TrackBar1->Location = System::Drawing::Point( 75, 30 );
      
      // Set the TickStyle property so there are ticks on both sides
      // of the TrackBar.
      TrackBar1->TickStyle = TickStyle::Both;
      
      // Set the minimum and maximum number of ticks.
      TrackBar1->Minimum = 10;
      TrackBar1->Maximum = 100;
      
      // Set the tick frequency to one tick every ten units.
      TrackBar1->TickFrequency = 10;
      
      // Associate the event-handling method with the 
      // ValueChanged event.
      TrackBar1->ValueChanged += gcnew System::EventHandler( this, &Form1::TrackBar1_ValueChanged );
      this->Controls->Add( this->TrackBar1 );
   }

   // Handle the TrackBar.ValueChanged event by calculating a value for
   // TextBox1 based on the TrackBar value.  
   void TrackBar1_ValueChanged( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      TextBox1->Text = (System::Math::Round( TrackBar1->Value / 10.0 )).ToString();
   }

//Declare a new TrackBar object.
internal System.Windows.Forms.TrackBar TrackBar1;

// Initalize the TrackBar and add it to the form.
private void InitializeTrackBar()
{
    this.TrackBar1 = new System.Windows.Forms.TrackBar();
    TrackBar1.Location = new System.Drawing.Point(75, 30);

    // Set the TickStyle property so there are ticks on both sides
    // of the TrackBar.
    TrackBar1.TickStyle = TickStyle.Both;

    // Set the minimum and maximum number of ticks.
    TrackBar1.Minimum = 10;
    TrackBar1.Maximum = 100;

    // Set the tick frequency to one tick every ten units.
    TrackBar1.TickFrequency = 10;

    // Associate the event-handling method with the 
    // ValueChanged event.
    TrackBar1.ValueChanged += 
        new System.EventHandler(TrackBar1_ValueChanged);
    this.Controls.Add(this.TrackBar1);
}


// Handle the TrackBar.ValueChanged event by calculating a value for
// TextBox1 based on the TrackBar value.  
private void TrackBar1_ValueChanged(object sender, System.EventArgs e)
{
    TextBox1.Text = (System.Math.Round(TrackBar1.Value/10.0)).ToString();
}

'Declare a new TrackBar object.
Friend WithEvents TrackBar1 As System.Windows.Forms.TrackBar

' Initalize the TrackBar and add it to the form.
Private Sub InitializeTrackBar()
    Me.TrackBar1 = New System.Windows.Forms.TrackBar

    ' Set the TickStyle property so there are ticks on both sides
    ' of the TrackBar.
    TrackBar1.TickStyle = TickStyle.Both

    ' Set the minimum and maximum number of ticks.
    TrackBar1.Minimum = 10
    TrackBar1.Maximum = 100

    ' Set the tick frequency to one tick every ten units.
    TrackBar1.TickFrequency = 10

    TrackBar1.Location = New System.Drawing.Point(75, 30)
    Me.Controls.Add(Me.TrackBar1)
End Sub


' Handle the TrackBar.ValueChanged event by calculating a value for
' TextBox1 based on the TrackBar value.  
Private Sub TrackBar1_ValueChanged(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles TrackBar1.ValueChanged
    TextBox1.Text = System.Math.Round(TrackBar1.Value / 10)
End Sub

Remarques

Vous pouvez utiliser cet événement pour mettre à jour d’autres contrôles lorsque la valeur représentée dans la barre de suivi change.You can use this event to update other controls when the value represented in the track bar changes.

Pour plus d'informations sur la gestion des événements, voir gestion et déclenchement d’événements.For more information about handling events, see Handling and Raising Events.

S’applique à