Three years ago, listening to the then brother recommended, bought Chiang waves of a book on the framework of GIS plug-ins. At that time while reading one of the examples of the complete realization of the case, the profit is shallow. Later, as a result of the project needs, also made a plug-in C/s system, with the MEF provided by Microsoft's framework. In this system, the communication of the Plug-ins and plug-ins not covered by Chiang's waves in his book was completed. However, the Chiang-wave book, which involves many of the underlying content of the plug-in system, is particularly worth learning about the design of plug-in engines. Recently, I have a summary of the example that I realized in my year, and share it with all of you.
1. The composition of the plug-in framework
(1). Framework is divided into host program and plug-in object two parts
(2). Two-part interaction based on a public communication contract
(3). Host programs can exist independently
2. Reasons for using Plug-ins
(1). The ability to extend a program without having to recompile and publish the program
(2). You can add new functionality to your program without the need for program source code
(3). Be flexible when the business logic of a program changes constantly and new rules are added frequently
3. The general implementation technology of the plug-in
(1). Plug-ins based on dynamic-link library DLLs
(2). com-based Plug-ins
(3). The plug-in based on reflection technology