PropertyChangedCallback PropertyChangedCallback PropertyChangedCallback PropertyChangedCallback Delegate

Definizione

Rappresenta il callback che viene richiamato quando cambia il valore effettivo di una proprietà di dipendenza.Represents the callback that is invoked when the effective property value of a dependency property changes.

public delegate void PropertyChangedCallback(DependencyObject ^ d, DependencyPropertyChangedEventArgs e);
public delegate void PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e);
type PropertyChangedCallback = delegate of DependencyObject * DependencyPropertyChangedEventArgs -> unit
Public Delegate Sub PropertyChangedCallback(d As DependencyObject, e As DependencyPropertyChangedEventArgs)

Parametri

d
DependencyObject DependencyObject DependencyObject DependencyObject

Oggetto DependencyObject per la cui proprietà è stato modificato il valore.The DependencyObject on which the property has changed value.

e
DependencyPropertyChangedEventArgs DependencyPropertyChangedEventArgs DependencyPropertyChangedEventArgs DependencyPropertyChangedEventArgs

Dati dell'evento emessi da qualsiasi evento che tiene traccia delle modifiche al valore effettivo di questa proprietà.Event data that is issued by any event that tracks changes to the effective value of this property.

Ereditarietà
PropertyChangedCallbackPropertyChangedCallbackPropertyChangedCallbackPropertyChangedCallback

Esempi

Nell'esempio seguente viene registrata una nuova proprietà di dipendenza utilizzando la firma che specifica PropertyChangedCallbackun oggetto.The following example registers a new dependency property, using the signature that specifies a PropertyChangedCallback. PropertyChangedCallback Viene utilizzato per creare un callback che modifica una proprietà interna ogni volta che la proprietà pubblica viene modificata.The PropertyChangedCallback is used to create a callback that changes an internal property whenever the public property changes.

public static readonly DependencyProperty AquariumGraphicProperty = DependencyProperty.Register(
  "AquariumGraphic",
  typeof(Uri),
  typeof(AquariumObject),
  new FrameworkPropertyMetadata(null,
      FrameworkPropertyMetadataOptions.AffectsRender, 
      new PropertyChangedCallback(OnUriChanged)
  )
);
Public Shared ReadOnly AquariumGraphicProperty As DependencyProperty = DependencyProperty.Register("AquariumGraphic", GetType(Uri), GetType(AquariumObject), New FrameworkPropertyMetadata(Nothing, FrameworkPropertyMetadataOptions.AffectsRender, New PropertyChangedCallback(AddressOf OnUriChanged)))
private static void OnUriChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
  Shape sh = (Shape) d;
  sh.Fill = new ImageBrush(new BitmapImage((Uri)e.NewValue));
}
Private Shared Sub OnUriChanged(ByVal d As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
    Dim sh As Shape = CType(d, Shape)
    sh.Fill = New ImageBrush(New BitmapImage(CType(e.NewValue, Uri)))
End Sub

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