Design And Implementation Of Online Education Platform Based On Improved MVVM

With the rapid development of the economy,the number of users of Android smartphones has increased year by year,and the market share of Android systems in the field of smart phones has exceeded 80%.As an aid to classrooms,online classes,and tutoring,online teaching and learning platforms based on Android are more common.In view of the traditional education methods and the existing online teaching and learning platform,this thesis develops an online Q&A and online class APP based on the Android platform.The app includes two clients,the student and the teacher.The main function is to ask questions on the student side,the teacher to grab the order and answer the questions;the teacher to develop the course,the student to make an appointment and to attend the class online.The APP front end uses XML and Activity to write the interface,and uses the relative layout instead of the nested layout to reduce the overdraw of the interface.The APP background uses the improved MVVM(Model-View-ViewModel)architecture in this thesis,uses LiveData instead of the cumbersome way of defining DataBinding in XML,and integrates RxJava with Retrofit as a network request method,Retrofit takes advantage of Java object-oriented to reduce the coupling between components and make the use of network requests more convenient.The server uses Tomcat and Spring as the server platform and MongoDB as the database.Spring can make native servlet classes correspond to methods,which makes the project structure clearer.In addition,in the MVVM framework,additional WebSocket full-duplex communication is used as the communication mode between the two clients,and the user-based collaborative filtering recommendation system is used to help the student to select the teacher.The main innovation of this thesis lies in the exploration and research of architecture.This project APP is based on Google's new component released at the I/O conference in 2018.It proposes an Android-side framework based on MVVM and is used for the development of this project.The framework encapsulates Retrofit and RxJava as a network request flow and uses annotations.,reflection and dynamic proxy integrate WebSocket related functions into the process of Retrofit,and abstract BaseActivity,BaseViewModel,BaseModel as the base class of logic flow,so that developers only need to pay attention to the respective functions of the implementation class in actual development.The logic flow only needs to implement the corresponding interface.This project is used to help students complete homework assignments.The two functions of question and answer and appointment are to fulfill the two needs of students,and expand the connection between teachers and students,which has certain practicability.In terms of development,the architecture proposed and implemented in this paper can also optimize the network request and callback process to a certain extent and reduce redundant code.