(I am a self learner, and self-study is very hard. Self learners have a deep understanding. The most troublesome thing is how to find a good textbook and learn more smoothly, which can only be explored in the dark. It is not only the pain of skin and flesh, but also the pain of the heart. It is lonely to guard the cold heart. As Ma Yun said, "Only the left hand can warm the right hand, and then the right hand can warm the left hand". Let's each count our hands. The book "Android SDK Program Design and Development Model" is really good, which is my personal conclusion after reading the book. For your understanding of the book, I scanned the contents of the book and a paragraph at the beginning. Due to the copyright, it is impossible to scan all of them. You can see from some of the scanning content that the author is well intentioned. The explanation is easy to understand, from "lead" to "deep". Even the LOG command line for debugging code is plugged in, thoughtful and detailed, making the reader feel safe and smooth everywhere. Of course, readers with different bases and receptive abilities still have different conclusions. But I have compared the books I have seen, and I think it is a good book to guide the program baby to the program youth. If you have the book, you can see that, for example, the book can be opened normally in the latest version of Android programming system. What I have done, for example, is concise and clean. The explanation content is clearly displayed in front of me. The key points are outstanding and the difficulties are shallow. It is suitable for self-study. After learning this book, the basic summary of Android programming will be clearly printed in the mind. This document includes the following annexes:)