A class inherits all interface implementations provided by its base classes. Without explicitly re-implementing an interface, a derived class cannot in any way alter the interface mappings it inherits from its base classes. [Example: For example, in the declarations the Paint method in TextBox hides the Paint method in Control, but it does not alter the mapping of Control.Paint onto IControl.Paint, and calls to Paint through class instances and interface instances will have the following effects end example] However, when an interface method is mapped onto a virtual method in a class, it is possible for derived classes to override the virtual method and alter the implementation of the interface. [Example: For example, rewriting the declarations above to the following effects will now be observed end example] Since explicit interface member implementations cannot be declared virtual, it is not possible to override an explicit interface member implementation. However, it is perfectly valid for an explicit interface member implementation to call another method, and that other method can be declared virtual to allow derived classes to override it. [Example: For example Here, classes derived from Control can specialize the implementation of IControl.Paint by overriding the PaintControl method. end example]