Invalidates the measurement state (layout) for the element.
Assembly: PresentationCore (in PresentationCore.dll)
Calling this method also calls InvalidateArrange internally, there is no need to call and InvalidateArrange in succession. After the invalidation, the element will have its layout updated, which will occur asynchronously, unless UpdateLayout is called to force a synchronous layout change.
The WPF framework-level layout system does its own handling of changes in the visual tree of an element, and in most common layout invalidation cases the layout system is calling the equivalent of this method when necessary. You should only call this method if you are producing a complete layout implementation, which does direct manipulation of the element tree, or similar advanced scenarios. One such advanced scenario is if you are creating a PropertyChangedCallback for a dependency property that is not on a Freezable or FrameworkElement derived class that still influences the measure pass of layout when it changes.
Frequent calls to or in particular to UpdateLayout have significant performance consequences. Therefore, avoid calling this method unless you absolutely require precise layout state for subsequent calls to other APIs in your code.