A, definitions,

ContentProvider, or ContentProvider, is one of the four components of Android


Second, the role of

Data exchange and sharing between processes, i.e. cross-process communication (image source)





Third, the principle of

At the bottom of ContentProvider is the Binder mechanism in Android


Four, specific use

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ContentResolve class

  • Function:

Manage operations between different ContentProviders in a unified manner

1. Use urls to manipulate data in different ContentProviders

External processes interact with the ContentProvider class through the ContentResolver class

  • Why use the ContentResolver class to interact with the ContentProvider class instead of accessing the ContentProvider class directly?

Generally speaking, an application needs to use multiple ContentProviders. If it needs to understand the different implementations of each ContentProvider to complete data interaction, the operation cost is high and the difficulty is great

A ContentResolver class is added to the ContentProvider class to manage all contentProviders.


advantages

1, safety

ContentProvider provides a secure environment for data interaction between applications. It allows you to open your application data to other applications for adding, deleting, modifying, and checking as required without worrying about security problems caused by directly opening database permissions.


2. Easy and efficient access

Compared with other data sharing methods, data access methods vary depending on the data storage mode:

  • When data is shared using files, read and write data needs to be performed.
  • Using SharedPreferences to share data requires reading and writing data using the SharedPreferences API, which makes accessing data complicated and difficult.
  • This ayong ContentProvider decouples the storage mode of the underlying data, so that no matter what the storage mode of the underlying data is, the external access to the data is unified, which makes access simple and efficient.



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