ScrollEventHandler ScrollEventHandler ScrollEventHandler ScrollEventHandler Delegate

Definizione

Rappresenta il metodo che gestirà l'evento Scroll di un oggetto DataGridView, ScrollBar, TrackBar o DataGrid.Represents the method that handles the Scroll event of a DataGridView, ScrollBar, TrackBar, or DataGrid.

public delegate void ScrollEventHandler(System::Object ^ sender, ScrollEventArgs ^ e);
public delegate void ScrollEventHandler(object sender, ScrollEventArgs e);
type ScrollEventHandler = delegate of obj * ScrollEventArgs -> unit
Public Delegate Sub ScrollEventHandler(sender As Object, e As ScrollEventArgs)

Parametri

sender
Object Object Object Object

Origine dell'evento.The source of the event.

e
ScrollEventArgs ScrollEventArgs ScrollEventArgs ScrollEventArgs

Oggetto ScrollEventArgs che contiene i dati dell'evento.A ScrollEventArgs that contains the event data.

Ereditarietà
ScrollEventHandlerScrollEventHandlerScrollEventHandlerScrollEventHandler

Esempi

Nell'esempio di codice riportato di seguito viene illustrato l'utilizzo di questo tipo.The following code example demonstrates the use of this type.

void AddMyScrollEventHandlers()
{
   // Create and initialize a VScrollBar.
   VScrollBar^ vScrollBar1 = gcnew VScrollBar;

   // Add event handlers for the OnScroll and OnValueChanged events.
   vScrollBar1->Scroll += gcnew ScrollEventHandler( this, &Form1::vScrollBar1_Scroll );
   vScrollBar1->ValueChanged += gcnew EventHandler( this, &Form1::vScrollBar1_ValueChanged );
}

// Create the ValueChanged event handler.
void vScrollBar1_ValueChanged( Object^ /*sender*/, EventArgs^ /*e*/ )
{
   // Display the new value in the label.
   label1->Text = String::Format( "vScrollBar Value:(OnValueChanged Event) {0}", vScrollBar1->Value );
}

// Create the Scroll event handler.
void vScrollBar1_Scroll( Object^ /*sender*/, ScrollEventArgs^ e )
{
   // Display the new value in the label.
   label1->Text = String::Format( "VScrollBar Value:(OnScroll Event) {0}", e->NewValue );
}

void button1_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
{
   // Add 40 to the Value property if it will not exceed the Maximum value.
   if ( vScrollBar1->Value + 40 < vScrollBar1->Maximum )
   {
      vScrollBar1->Value = vScrollBar1->Value + 40;
   }
}
private void AddMyScrollEventHandlers()
 {
    // Create and initialize a VScrollBar.
    VScrollBar vScrollBar1 = new VScrollBar();
 
    // Add event handlers for the OnScroll and OnValueChanged events.
    vScrollBar1.Scroll += new ScrollEventHandler(
       this.vScrollBar1_Scroll);
    vScrollBar1.ValueChanged += new EventHandler(
       this.vScrollBar1_ValueChanged); 
 }
 
 // Create the ValueChanged event handler.
 private void vScrollBar1_ValueChanged(Object sender, 
                                       EventArgs e)
 {
     // Display the new value in the label.
     label1.Text = "vScrollBar Value:(OnValueChanged Event) " + vScrollBar1.Value.ToString();
 }
 
 // Create the Scroll event handler.
 private void vScrollBar1_Scroll(Object sender, 
                                 ScrollEventArgs e)
 {
     // Display the new value in the label.
     label1.Text = "VScrollBar Value:(OnScroll Event) " + e.NewValue.ToString();
 }
 
 private void button1_Click(Object sender, 
                           EventArgs e)
 {
    // Add 40 to the Value property if it will not exceed the Maximum value.
    if (vScrollBar1.Value + 40 < vScrollBar1.Maximum)
    {
        vScrollBar1.Value = vScrollBar1.Value + 40;
    }
 }
 
Private Sub AddMyScrollEventHandlers()
    ' Create and initialize a VScrollBar.
    Dim vScrollBar1 As New VScrollBar()
    
    ' Add event handlers for the OnScroll and OnValueChanged events.
    AddHandler vScrollBar1.Scroll, AddressOf Me.vScrollBar1_Scroll
    AddHandler vScrollBar1.ValueChanged, AddressOf Me.vScrollBar1_ValueChanged
End Sub    

' Create the ValueChanged event handler.
Private Sub vScrollBar1_ValueChanged(sender As Object, e As EventArgs)
    ' Display the new value in the label.
    label1.Text = "vScrollBar Value:(OnValueChanged Event) " & _
        vScrollBar1.Value.ToString()
End Sub    

' Create the Scroll event handler.
Private Sub vScrollBar1_Scroll(sender As Object, e As ScrollEventArgs)
    ' Display the new value in the label.
    label1.Text = "VScrollBar Value:(OnScroll Event) " & _
        e.NewValue.ToString()
End Sub    

Private Sub button1_Click(sender As Object, e As EventArgs)
    ' Add 40 to the Value property if it will not exceed the Maximum value.
    If vScrollBar1.Value + 40 < vScrollBar1.Maximum Then
        vScrollBar1.Value = vScrollBar1.Value + 40
    End If
End Sub

Commenti

Quando si crea un delegato ScrollEventArgs, si identifica il metodo che gestirà l'evento.When you create a ScrollEventArgs delegate, you identify the method that will handle the event. Per associare l'evento al gestore eventi in uso, aggiungere all'evento un'istanza del delegato.To associate the event with your event handler, add an instance of the delegate to the event. Il gestore eventi viene chiamato ogni volta che si verifica l'evento, a meno che non venga rimosso il delegato.The event handler is called whenever the event occurs, unless you remove the delegate. Per ulteriori informazioni sui delegati del gestore eventi, vedere gestione e generazione di eventi.For more information about event handler delegates, see Handling and Raising Events.

Metodi di estensione

GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate)

Ottiene un oggetto che rappresenta il metodo rappresentato dal delegato specificato.Gets an object that represents the method represented by the specified delegate.

Si applica a

Vedi anche