DependencyProperty.IsValidType Method (Object)
Determines whether a specified value is acceptable for this dependency property's type, as checked against the property type provided in the original dependency property registration.
Assembly: WindowsBase (in WindowsBase.dll)
A value of null is a valid type for reference type dependency properties, or for a Nullable<T> dependency property, and would return true for these cases. In cases where the dependency property is neither a reference nor a Nullable<T> type, will return false for a null value rather than raise an exception.
Available since 3.0