FrameworkPropertyMetadata Constructor (Object, PropertyChangedCallback)


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Initializes a new instance of the FrameworkPropertyMetadata class with the provided default value and specified PropertyChangedCallback callback.

Namespace:   System.Windows
Assembly:  PresentationFramework (in PresentationFramework.dll)

public FrameworkPropertyMetadata(
	object defaultValue,
	PropertyChangedCallback propertyChangedCallback


Type: System.Object

The default value of the dependency property, usually provided as a value of a specific type.

Type: System.Windows.PropertyChangedCallback

A reference to a handler implementation that the property system will call whenever the effective value of the property changes.

Exception Condition

defaultValue is set to UnsetValue; see Remarks.

The type of the value provided for defaultValue must match or be related to the type specified in the original registration of the dependency property that this metadata will be applied to. Mismatches between metadata default value type and the type of the dependency property it is being applied to can be difficult to debug, because the mismatch is not detectable during compilation. The property system does not evaluate the effective value of a property until run time, so the result of a default value type/property type mismatch is a run-time error.

The value UnsetValue has special meaning in the property system, and cannot be used as a dependency property default value.

The following example calls this constructor signature:

static FrameworkPropertyMetadata fpm;
fpm = new FrameworkPropertyMetadata(
    new PropertyChangedCallback(OnCurrentReadingChanged)

.NET Framework
Available since 3.0
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