When you write your own class library, you can write some commonly used function integrations and add them to the project for future use. You can also upload them to open source websites such as code4App and github. Of course, you can also Need to pass its review.

When writing, you can refer to the specifications for making multiple open source codes on the Internet, and it is also convenient to call.

I saw that this question was asked last year. I think you should have learned it a long time ago, or you are already a master. You can take me to study with you when you have nothing to do.