FrameworkPropertyMetadata Constructor (Object, FrameworkPropertyMetadataOptions, PropertyChangedCallback, CoerceValueCallback)

FrameworkPropertyMetadata Constructor (Object, FrameworkPropertyMetadataOptions, PropertyChangedCallback, CoerceValueCallback)

Initializes a new instance of the FrameworkPropertyMetadata class with the provided default value and framework metadata options, and specified callbacks.

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

public FrameworkPropertyMetadata(
	Object defaultValue,
	FrameworkPropertyMetadataOptions flags,
	PropertyChangedCallback propertyChangedCallback,
	CoerceValueCallback coerceValueCallback


Type: System.Object
The default value of the dependency property, usually provided as a specific type.
Type: System.Windows.FrameworkPropertyMetadataOptions
The metadata option flags (a combination of FrameworkPropertyMetadataOptions values). These options specify characteristics of the dependency property that interact with systems such as layout or data binding.
Type: System.Windows.PropertyChangedCallback
A reference to a handler implementation that the property system will call whenever the effective value of the property changes.
Type: System.Windows.CoerceValueCallback
A reference to a handler implementation that will be called whenever the property system calls CoerceValue against this property.


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.

Values marked as set flags in the flags parameter will set the Boolean value of FrameworkPropertyMetadata properties that match that FrameworkPropertyMetadataOptions flag's name to true. You can still change the values of the properties in the metadata, as long as the metadata has not yet been applied to a specific property system operation.

The following example calls this constructor signature:

static FrameworkPropertyMetadata fpm;


fpm = new FrameworkPropertyMetadata(
    (FrameworkPropertyMetadataOptions.AffectsRender |
    new PropertyChangedCallback(OnCurrentReadingChanged),
    new CoerceValueCallback(CoerceCurrentReading)

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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