1. Add classes and third-party jar packages that don't need to be confused in the proguard-project.txt file.

This is a class that does not need to be confused in its own package. If some classes call jni, there is no need to confuse them, otherwise an error will occur. In addition, if other projects are introduced into the project as libraries, some classes of these projects should not be confused.

This is to avoid confusion among third-party jars in the project.

In addition, add the above words, otherwise the console will report a warning warning.

2. Delete the # sign before proguard.config = $ {SDK.dir}/tools/proguard-android.txt: proguard-project.txt in the project.properties file.

Finally, just export the signature package.