DependencyPropertyChangedEventArgs.NewValue DependencyPropertyChangedEventArgs.NewValue DependencyPropertyChangedEventArgs.NewValue DependencyPropertyChangedEventArgs.NewValue Property

Definición

Obtiene el valor de la propiedad después del cambio.Gets the value of the property after the change.

public:
 property System::Object ^ NewValue { System::Object ^ get(); };
public object NewValue { get; }
member this.NewValue : obj
Public ReadOnly Property NewValue As Object

Valor de propiedad

Valor de la propiedad después del cambio.The property value after the change.

Ejemplos

En el ejemplo siguiente se DependencyPropertyChangedEventArgs usa la clase en el contexto PropertyChangedCallback de para una propiedad determinada de una clase personalizada que también define eventos.The following example uses the DependencyPropertyChangedEventArgs class in the context of a PropertyChangedCallback for a particular property of a custom class that also defines events. La devolución de llamada toma los resultados de los valores antiguos y nuevos del sistema de propiedades como DependencyPropertyChangedEventArgscomunicados por y los empaqueta en una clase RoutedPropertyChangedEventArgs<T>de argumentos de eventos diferentes.The callback takes the results of old and new values from the property system as communicated by DependencyPropertyChangedEventArgs, and repackages these into a different events arguments class RoutedPropertyChangedEventArgs<T>. Los nuevos argumentos se usan después como los datos para un evento "ValueChanged" definido por la clase personalizada y generados por ella.The new arguments are then used as the data for a "ValueChanged" event defined by and raised by the custom class.

public static readonly DependencyProperty ValueProperty =
    DependencyProperty.Register(
        "Value", typeof(decimal), typeof(NumericUpDown),
        new FrameworkPropertyMetadata(MinValue, new PropertyChangedCallback(OnValueChanged),
                                      new CoerceValueCallback(CoerceValue)));

private static object CoerceValue(DependencyObject element, object value)
{
    decimal newValue = (decimal)value;

    newValue = Math.Max(MinValue, Math.Min(MaxValue, newValue));

    return newValue;
}

private static void OnValueChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
    NumericUpDown control = (NumericUpDown)obj;

    RoutedPropertyChangedEventArgs<decimal> e = new RoutedPropertyChangedEventArgs<decimal>(
        (decimal)args.OldValue, (decimal)args.NewValue, ValueChangedEvent);
    control.OnValueChanged(e);
}
/// <summary>
/// Identifies the ValueChanged routed event.
/// </summary>
public static readonly RoutedEvent ValueChangedEvent = EventManager.RegisterRoutedEvent(
    "ValueChanged", RoutingStrategy.Bubble,
    typeof(RoutedPropertyChangedEventHandler<decimal>), typeof(NumericUpDown));

/// <summary>
/// Occurs when the Value property changes.
/// </summary>
public event RoutedPropertyChangedEventHandler<decimal> ValueChanged
{
    add { AddHandler(ValueChangedEvent, value); }
    remove { RemoveHandler(ValueChangedEvent, value); }
}
/// <summary>
/// Raises the ValueChanged event.
/// </summary>
/// <param name="args">Arguments associated with the ValueChanged event.</param>
protected virtual void OnValueChanged(RoutedPropertyChangedEventArgs<decimal> args)
{
    RaiseEvent(args);
}
Public Shared ReadOnly ValueProperty As DependencyProperty = DependencyProperty.Register("Value", GetType(Decimal), GetType(NumericUpDown), New FrameworkPropertyMetadata(MinValue, New PropertyChangedCallback(AddressOf OnValueChanged), New CoerceValueCallback(AddressOf CoerceValue)))

Private Shared Overloads Function CoerceValue(ByVal element As DependencyObject, ByVal value As Object) As Object
	Dim newValue As Decimal = CDec(value)

	newValue = Math.Max(MinValue, Math.Min(MaxValue, newValue))

	Return newValue
End Function

Private Shared Sub OnValueChanged(ByVal obj As DependencyObject, ByVal args As DependencyPropertyChangedEventArgs)
	Dim control As NumericUpDown = CType(obj, NumericUpDown)

	Dim e As New RoutedPropertyChangedEventArgs(Of Decimal)(CDec(args.OldValue), CDec(args.NewValue), ValueChangedEvent)
	control.OnValueChanged(e)
End Sub
''' <summary>
''' Identifies the ValueChanged routed event.
''' </summary>
Public Shared ReadOnly ValueChangedEvent As RoutedEvent = EventManager.RegisterRoutedEvent("ValueChanged", RoutingStrategy.Bubble, GetType(RoutedPropertyChangedEventHandler(Of Decimal)), GetType(NumericUpDown))

''' <summary>
''' Occurs when the Value property changes.
''' </summary>
Public Custom Event ValueChanged As RoutedPropertyChangedEventHandler(Of Decimal)
	AddHandler(ByVal value As RoutedPropertyChangedEventHandler(Of Decimal))
		MyBase.AddHandler(ValueChangedEvent, value)
	End AddHandler
	RemoveHandler(ByVal value As RoutedPropertyChangedEventHandler(Of Decimal))
		MyBase.RemoveHandler(ValueChangedEvent, value)
	End RemoveHandler
	RaiseEvent(ByVal sender As System.Object, ByVal e As RoutedPropertyChangedEventArgs(Of Decimal))
	End RaiseEvent
End Event
''' <summary>
''' Raises the ValueChanged event.
''' </summary>
''' <param name="args">Arguments associated with the ValueChanged event.</param>
Protected Overridable Sub OnValueChanged(ByVal args As RoutedPropertyChangedEventArgs(Of Decimal))
	MyBase.RaiseEvent(args)
End Sub

Comentarios

El tipo del valor proporcionado siempre se puede convertir al tipo de la propiedad de dependencia que se va a informar.The type of the value provided should always be castable to the type of the dependency property being reported.

Se aplica a