DependencyObject.ClearValue Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Clears the local value of a dependency property.
Assembly: System.Windows (in System.Windows.dll)
Parameters
- dp
- Type: System.Windows.DependencyProperty
The DependencyProperty identifier of the property to clear the value for.
Clearing the property value by calling ClearValue does not necessarily give a dependency property its default value. Clearing the property only specifically clears whatever local value may have been applied, but other factors in dependency property precedence (such as styles, or an animation) might still be applying a value.
The following example checks for an existing local value with ReadLocalValue. If there is a local value, as indicated by not returning UnsetValue, then the existing local value is removed by calling ClearValue.
public static bool ClearSetProperty(DependencyObject targetObject, DependencyProperty targetDP) { if (targetObject == null || targetDP == null) { throw new ArgumentNullException(); } object localValue = targetObject.ReadLocalValue(targetDP); if (localValue == DependencyProperty.UnsetValue) { return false; } else { targetObject.ClearValue(targetDP); return true; } }