清单部分：

<application
   android:allowBackup="true"
   android:backupAgent="my.package.MyBackupManagerClass">

<Meta-data android:name="com.google.android.backup.api_key" 
   android:value="my-generated-key-by-google-service" />

事实上,备份正在运行,但只使用本地传输,我已经使用bmgr备份/运行/恢复进行了测试：

bmgr list transports
  * android/com.android.internal.backup.LocalTransport
    com.google.android.gms/.backup.BackupTransportService

但是当尝试使用Google传输(云：com.google.android.gms / .backup.BackupTransportService)时,它无效,甚至无法从MyBackupAgentHelper调用我的onCreate().

我要提到的一点是,当我跑：
bmgr备份
bmgr跑

在运行命令之后,在logcat上显示了很多“现在暂存备份”(也显示我的应用程序包在此列表中)但它发生得非常快并且看起来事实上并没有完成备份,毕竟,甚至我的MyBackupHelper.onCreate()未被调用：

02-12 21:13:28.889: D/BackupManagerService(547): Now staging backup of com.google.android.talk
02-12 21:13:28.904: D/BackupManagerService(547): Now staging backup of com.google.android.dialer
02-12 21:13:28.907: D/BackupManagerService(547): Now staging backup of com.android.providers.settings
02-12 21:13:28.910: D/BackupManagerService(547): Now staging backup of com.sirma.mobile.bible.android
02-12 21:13:28.914: D/BackupManagerService(547): Now staging backup of com.android.sharedstoragebackup
02-12 21:13:28.919: D/BackupManagerService(547): Now staging backup of com.google.android.gm
02-12 21:13:28.922: D/BackupManagerService(547): Now staging backup of com.android.providers.userdictionary
02-12 21:13:28.926: D/BackupManagerService(547): Now staging backup of com.google.android.apps.genie.geniewidget
02-12 21:13:28.963: I/GmsBackupTransport(1409): Next backup will happen in 86399923 millis.
02-12 21:13:28.967: I/BackupManagerService(547): Backup pass finished.