C# DependencyObject.RemoveSelfAsInheritanceContext方法代码示例

 [FriendAccessAllowed] // Built into Base, also used by Framework.
 internal static void RemoveContextFromObject(
     DependencyObject context,
     DependencyObject oldValue )
 {
     if (context != null && oldValue.InheritanceContext == context)
     {
         context.RemoveSelfAsInheritanceContext(oldValue, null);
     }
 }

        //
        //  This method
        //  1. Adds or removes per-instance state on the container/child (push model)
        //  2. Processes a single value that needs per-instance storage
        //
        internal static void ProcessInstanceValue(
            DependencyObject    target,
            int                 childIndex,
            HybridDictionary    instanceValues,
            DependencyProperty  dp,
            int                 i,
            bool                apply)
        {
            // If we get this far, it's because there's a value
            // in the property value list of an active style that requires
            // per-instance storage.  The initialization (CreateInstaceData)
            // should have created the InstanceValues hashtable by now.
            Debug.Assert(instanceValues != null, "InstanceValues hashtable should have been created at initialization time.");

            InstanceValueKey key = new InstanceValueKey(childIndex, dp.GlobalIndex, i);

            if (apply)
            {
                // Store a sentinel value in per-instance StyleData.
                // The actual value is created only on demand.
                instanceValues[key] = NotYetApplied;
            }
            else
            {
                // Remove the instance value from the table
                object value = instanceValues[key];
                instanceValues.Remove(key);

                Expression expr;
                Freezable freezable;

                if ((expr = value as Expression)!= null)
                {
                    // if the instance value is an expression, detach it
                    expr.OnDetach(target, dp);
                }
                else if ((freezable = value as Freezable)!= null)
                {
                    // if the instance value is a Freezable, remove its
                    // inheritance context
                    target.RemoveSelfAsInheritanceContext(freezable, dp);
                }
            }
        }