Android (Java) Learning note 252:contentprovider Using Content Viewer 01

1. Content Viewer

Does not belong to the four components, only the content provider ContentProvider corresponding small function.

If the contents of the database are found to be changed, they will be observed immediately.

Here is the logical diagram:

When the data inside the bank in a application changes, the A application sends the data to a piece of public memory, and the memory watcher reads the data in the public memory. So that the database of a application is changed.

This mechanism is similar to the broadcast receiver principle, but for the broadcast receiver, the application that registers the receiver of the broadcast will receive the broadcast, so the efficiency is not good, so Google encapsulates an API application as: content Observer .

Android (Java) Learning note 252:contentprovider Using Content Viewer 01