Design patterns contain a large number of programming ideas, and it is not easy to teach and truly master them. There are many design pattern courses online, and most of them are relatively obscure and lack real application scenarios and framework source code support. After learning, you only know the shape but not the form. Its god. I know various design patterns, but don’t know how to use them in real projects. This course aims at the above problems. (1) The teaching method adopts diagram + framework source code analysis. (2) It systematically and comprehensively explains the design pattern, including the seven principles of design pattern, the six major relationships between UML class diagram and class, and 23 types of designs. Patterns and their classification, etc.