SharedPreferencesBackupHelper Class

Definition

[Android.Runtime.Register("android/app/backup/SharedPreferencesBackupHelper", DoNotGenerateAcw=true)]
public class SharedPreferencesBackupHelper : Android.App.Backup.FileBackupHelperBase, Android.App.Backup.IBackupHelper, IDisposable

[<Android.Runtime.Register("android/app/backup/SharedPreferencesBackupHelper", DoNotGenerateAcw=true)>]
type SharedPreferencesBackupHelper = class
    inherit FileBackupHelperBase
    interface IBackupHelper
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Inheritance

Object

JavaObject

Object

FileBackupHelperBase

SharedPreferencesBackupHelper

Attributes

RegisterAttribute

Implements

IBackupHelper IJavaObject IJavaPeerable IDisposable

Remarks

A helper class that can be used in conjunction with android.app.backup.BackupAgentHelper to manage the backup of android.content.SharedPreferences. Whenever a backup is performed, it will back up all named shared preferences that have changed since the last backup operation.

To use this class, the application's backup agent class should extend android.app.backup.BackupAgentHelper. Then, in the agent's BackupAgent#onCreate() method, an instance of this class should be allocated and installed as a backup/restore handler within the BackupAgentHelper framework. For example, an agent supporting backup and restore for an application with two groups of android.content.SharedPreferences data might look something like this:

import android.app.backup.BackupAgentHelper;
            import android.app.backup.SharedPreferencesBackupHelper;

            public class MyBackupAgent extends BackupAgentHelper {
                // The names of the SharedPreferences groups that the application maintains.  These
                // are the same strings that are passed to {@link Context#getSharedPreferences(String, int)}.
                static final String PREFS_DISPLAY = "displayprefs";
                static final String PREFS_SCORES = "highscores";

                // An arbitrary string used within the BackupAgentHelper implementation to
                // identify the SharedPreferenceBackupHelper's data.
                static final String MY_PREFS_BACKUP_KEY = "myprefs";

                // Allocate a helper and install it.
                public void onCreate() {
                    SharedPreferencesBackupHelper helper =
                            new SharedPreferencesBackupHelper(this, PREFS_DISPLAY, PREFS_SCORES);
                    addHelper(MY_PREFS_BACKUP_KEY, helper);
                }
            }

No further implementation is needed; the BackupAgentHelper mechanism automatically dispatches the BackupAgent#onBackup(android.os.ParcelFileDescriptor, BackupDataOutput, android.os.ParcelFileDescriptor) BackupAgent.onBackup() and BackupAgent#onRestore(BackupDataInput, int, android.os.ParcelFileDescriptor) BackupAgent.onRestore() callbacks to the SharedPreferencesBackupHelper as appropriate.

Java documentation for android.app.backup.SharedPreferencesBackupHelper.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.