如何使用Android Backup Service进行数据备份和恢复[页5]

javaCopy codepublic class MyBackupAgent extends BackupAgentHelper {

    // 定义备份的数据类型
    static final String PREFS_BACKUP_KEY = "prefs";
    static final String DATABASE_BACKUP_KEY = "database";

    @Override
    public void onCreate() {
        // 定义备份的数据类型
        SharedPreferencesBackupHelper prefsHelper =
                new SharedPreferencesBackupHelper(this, getPackageName() + "_preferences");
        addHelper(PREFS_BACKUP_KEY, prefsHelper);

        FileBackupHelper fileHelper = new FileBackupHelper(this, "my_file.txt");
        addHelper("file", fileHelper);

        SQLiteOpenHelper helper = new MyDatabaseHelper(this);
        SQLiteDatabase db = helper.getWritableDatabase();
        BackupHelper dbHelper = new SQLiteDatabaseBackupHelper(this, db, "my_database.db");
        addHelper(DATABASE_BACKUP_KEY, dbHelper);
    }
}

在上面的示例中，我们使用SharedPreferencesBackupHelper、FileBackupHelper和SQLiteDatabaseBackupHelper来备份SharedPreferences、文件和SQLite数据库。需要注意的是，我们需要提供每个备份数据类型的唯一标识符。