Reusing Code and Delegation

Go Up to Using Interfaces

One approach to reusing code with interfaces is to have one interfaced object contain, or be contained by another. Using properties that are object types provides an approach to containment and code reuse. To support this design for interfaces, the Delphi language has a keyword implements, that makes it easy to write code to delegate all or part of the implementation of an interface to a subobject.

Aggregation is another way of reusing code through containment and delegation. In aggregation, an outer object uses an inner object that implements interfaces which are exposed only by the outer object.

Topics

• Using Implements for Delegation
• Aggregation

See Also

• Using Interfaces with Procedures
• Implementing IInterface
• Using the as Operator with Interfaces
• Using Interfaces Across the Hierarchy
• Memory Management of Interface Objects
• Using Interfaces in Distributed Applications