DependencyObject.ClearValue Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Clears the local value of a property.
Overloads
| ClearValue(DependencyProperty) |
Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. |
| ClearValue(DependencyPropertyKey) |
Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. |
ClearValue(DependencyProperty)
Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier.
public:
void ClearValue(System::Windows::DependencyProperty ^ dp);public void ClearValue (System.Windows.DependencyProperty dp);member this.ClearValue : System.Windows.DependencyProperty -> unitPublic Sub ClearValue (dp As DependencyProperty)Parameters
The dependency property to be cleared, identified by a DependencyProperty object reference.
Exceptions
Attempted to call ClearValue(DependencyProperty) on a sealed DependencyObject.
Examples
The following example iterates all properties that have local values set on an object, then calls ClearValue to clear the values of each such property.
void RestoreDefaultProperties(object sender, RoutedEventArgs e)
{
UIElementCollection uic = Sandbox.Children;
foreach (Shape uie in uic)
{
LocalValueEnumerator locallySetProperties = uie.GetLocalValueEnumerator();
while (locallySetProperties.MoveNext())
{
DependencyProperty propertyToClear = locallySetProperties.Current.Property;
if (!propertyToClear.ReadOnly) { uie.ClearValue(propertyToClear); }
}
}
}
Private Sub RestoreDefaultProperties(ByVal sender As Object, ByVal e As RoutedEventArgs)
Dim uic As UIElementCollection = Sandbox.Children
For Each uie As Shape In uic
Dim locallySetProperties As LocalValueEnumerator = uie.GetLocalValueEnumerator()
While locallySetProperties.MoveNext()
Dim propertyToClear As DependencyProperty = locallySetProperties.Current.Property
If Not propertyToClear.ReadOnly Then
uie.ClearValue(propertyToClear)
End If
End While
Next
End Sub
Remarks
Clearing the property value by calling ClearValue does not necessarily give a dependency property the default value that is specified in the dependency property metadata. Clearing the property only specifically clears whatever local value may have been applied. For more information, see Dependency Property Value Precedence.
See also
Applies to
ClearValue(DependencyPropertyKey)
Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey.
public:
void ClearValue(System::Windows::DependencyPropertyKey ^ key);public void ClearValue (System.Windows.DependencyPropertyKey key);member this.ClearValue : System.Windows.DependencyPropertyKey -> unitPublic Sub ClearValue (key As DependencyPropertyKey)Parameters
The key for the dependency property to be cleared.
Exceptions
Attempted to call ClearValue(DependencyProperty) on a sealed DependencyObject.
Remarks
A DependencyPropertyKey identifies a read-only dependency property for property system operations. Classes that define read-only dependency properties should not expose this key with public access. A publicly exposed key would provide a public code pathway that negated the read-only character of the property, if methods such as ClearValue or SetValue could be called outside the class or assembly, referencing the key.
Clearing the property value by calling ClearValue does not necessarily give a dependency property the default value that is specified in the dependency property metadata. Clearing the value only specifically clears whatever local value may have been applied. For more information, see Dependency Property Value Precedence.
