Working with ArcGIS base classes

The ESRI.ArcGIS.ADF.Local assembly provides a number of base classes to help you create custom components for ArcGIS. The classes are abstract classes that cannot be instantiated and frequently contain only partial or no implementation code. They can only be used by being inherited by another class. Although similar in concept as interfaces, they differ significantly from interfaces in that a class might implement any number of interfaces, but it can inherit from only one abstract class. 

Along with the samples and ArcGIS item templates available in the .NET software development kit (SDK), they show how to implement these common ArcGIS components more efficiently.

The following table shows the base classes (under ESRI.ArcGIS.ADF.BaseClasses namespace) that can be inherited by their corresponding custom components, along with the available ArcGIS item templates or samples:

Custom components	Base classes	Item templates and samples
Commands and tools
Command	BaseCommand	Template—ArcGIS, Base Command
Tool	BaseTool	Template—ArcGIS, Base Tool
Command bars
Toolbar	BaseToolbar	Template—ArcGIS, Base Toolbar
Menu	BaseMenu	Template—ArcGIS, Base Menu
Context menu (Desktop)	BaseMenu	Template—ArcGIS, Desktop, Context Menu
Layers
Custom layer	BaseCustomLayer	Sample: RSS weather layer
Custom globe layer	BaseCustomGlobeLayer	Sample: RSS weather 3D layer
Custom dynamic layer	BaseDynamicLayer	Sample: Dynamic display layer

The following screen shot shows some of the ArcGIS item templates in Visual Studio:

Keep in mind, Inheritance of ArcGIS COM types in .NET is not supported. If the ArcGIS base classes do not contain the components you want, implement interfaces to customize your classes.