IPC for Android basic

1. There are two ways for Android Process Communication: intent and process service.

(1) steps for implementing remote services:

1) Use the aidl language to define cross-process service interfaces

2) Implement the methods and attributes defined in interfaces in specific service classes based on the APIS defined in aidl.

3) Call the cross-process service through the same aidl interface file in the components that need to call the cross-process service

(2) parcel is a container for data transfer between processes in the Android system, but cannot be stored on persistent storage devices.