Class ConvertNullToUnsetValue

This converter will return DependencyProperty.UnsetValue if the input value is null. This is needed to work around an issue with PriorityBindings. If the first Binding in a PriorityBinding has a null value, then the binding might still succeed if the Path="." (for example, if the target property is a string then null is a valid value). In this scenario, setting the TargetNullValue="DependencyProperty.UnsetValue" doesn't work. For example, this will use the first Binding if the value of the source is null: PriorityBinding Binding Path="." TargetNullValue="{x:Static DependencyProperty.UnsetValue}" Binding Path="PropertyB" /PriorityBinding The expected result is that the second binding would be used if the source value is null. Using this converter to convert null values into DependencyProperty.UnsetValue works around the problem.

Inheritance

object

ConvertNullToUnsetValue

Implements

IValueConverter

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Phoenix.Aruba.Converters

Assembly: Phoenix.Plugin.Aruba.dll

Syntax

public class ConvertNullToUnsetValue : IValueConverter

Methods

View Source

Convert(object, Type, object, CultureInfo)

Converts a given input value to DependencyProperty.UnsetValue if it is null. It passes it through unchanged if it is not null.

Declaration

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)

Parameters

Type	Name	Description
object	value	The input value to be converted.
Type	targetType	The parameter is not used.
object	parameter	The parameter is not used.
CultureInfo	culture	The parameter is not used.

Returns

Type	Description
object	DependencyProperty.UnsetValue if the input value is null. Otherwise it returns the input value unchanged.