The Research And Realization Of Instant Messaging System Based On .NET

Instant messaging is one of the most popular applications based on Network. Chatting is the basic function of instant messaging system, other functions such as video chatting, SMS are also integrated in instant messaging system, and instant messaging is a new communication method for human following the information times. With its evolution to communication multimedia and entering to industries and educational applications, instant messaging is being investigated extensively.This thesis is the subproject of "Distant education complicated application platform of Chinese Communists" instant messaging subsystem. Its main task is to provide a complicated studying and communicating platform for all Chinese Communists. They can discuss topics what they care about and experiences of studying and laboring. On the other hand, interaction between each other makes the transmitting and feedback of information easy.The key techniques of instant messaging system based on .NET technique are deeply studied in this thesis. A summary of the concepts, service modes, communication protocols, communication principles and methods of implementation of instant messaging system are also made.Firstly, features of various popular instant messaging software are discussed and analyzed, then the function of instant messaging system is confirmed. The framework structure of instant messaging server is designed, and some key components, such as data package processing, XML application and NAT firewall traversal are interpreted exactly. As one of the work of this thesis, the XML protocol format is applied to the design of communication protocol. So this system has the features of the extensibility and advantages of Cross-platform information exchange.Secondly, the important modules of client and server of instant messaging system is presented in detail, such as the design, implementation and function of each module, and flow chart of each module is showed. Furthermore, the online updating module on client computer which applied the background automatically updating, it is easier to use, for example, it can help many people who are not familiar with the computer operations.Finally, the test results and analysis reports for this instant messaging system is put forward. A large amount of experimental data shows that this system can be expanded and implemented easily. It is high reliable and efficiency aware.