相关疑难解决方法(0)

好吧,所以我正在尝试将数据备份实施到我的应用程序中,并且一直在遵循本指南.我已经实现了我的BackupAgentHelper使用SharedPreferencesBackupHelper.我没有得到任何错误,并且我确定dataChanged()在所有首选项更改后调用,但是当我测试备份(`adb shell bmgr run)时,我在LogCat中获取此信息:

07-07 12:29:00.258: V/BackupManagerService(291): Scheduling immediate backup pass
07-07 12:29:00.258: V/BackupManagerService(291): Running a backup pass
07-07 12:29:00.258: V/BackupManagerService(291): clearing pending backups
07-07 12:29:00.258: V/PerformBackupTask(291): Beginning backup of 1 targets
07-07 12:29:00.289: V/BackupServiceBinder(291): doBackup() invoked
07-07 12:29:00.289: D/PerformBackupTask(291): invokeAgentForBackup on @pm@
07-07 12:29:00.297: I/PerformBackupTask(291): no backup data written; not calling transport

所以为了参考,在我的清单中我添加了:

<application
        android:allowBackup="true"
        android:backupAgent="com.kcoppock.sudoku.SudokuBackupAgent"

以及

<meta-data
        android:name="com.google.android.backup.api_key"
        android:value="my_key_goes_here" />

我的BackupAgentHelper实现如下:

public class SudokuBackupAgent extends BackupAgentHelper {
    static final String …