从云备份和恢复应用数据时崩溃

Question

我通过以下链接http://developer.android.com/training/cloudsync/backupapi.html将应用数据同步到Google服务器。我做了文档中提到的所有步骤。但每次我尝试恢复数据都会崩溃。我写的代码如下所示。

清单文件

<application
        android:allowBackup="true"
        android:restoreAnyVersion="true"
        android:backupAgent="TheBackupAgent"
        android:icon="@drawable/icn_launcher"
        android:label="@string/app_name" >

        <meta-data android:name="com.google.android.backup.api_key" 
            android:value="AEdP-_NxcBxt_Zq56pCzqg" />

        <activity
            android:name=".BackUpAvtivity"
            android:configChanges="orientation"
            android:label="@string/app_name"
            android:screenOrientation="portrait"
            android:theme="@android:style/Theme.Light.NoTitleBar" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
</application>

** TheBackUpAgent Class **

public class TheBackupAgent extends BackupAgentHelper
{
    // A key to uniquely identify the set of backup data
    static final String FILES_BACKUP_KEY = "myfiles";

    BackupManager bm;

    // Allocate a helper and add it to the backup agent
    @Override
    public void onCreate() 
    {
        FileBackupHelper helper = new FileBackupHelper(this, "HistoryDates", "EndDates", "Settings",
                "Reminders", "LoveDates", "Weights", "Temperatures", "Notes");
        addHelper(FILES_BACKUP_KEY, helper);                
    }

    public void requestBackup()
    {       
        bm = new BackupManager(this);
        bm.dataChanged();
    }

    public void restoreData()
    {
        bm = new BackupManager(this);
        bm.requestRestore(
                new RestoreObserver() 
                {
                    public void restoreStarting(int error) 
                    {
                        System.out.println(error);
                    }
                }
        );

    }
}

BackUpAvtivity Class

在这个课程中，我有两个按钮用于备份，一个用于恢复。每个按钮内的代码都是。

buttonBackup.setOnClickListener(new Button.OnClickListener()
                    {
                        public void onClick(View v) 
                        {
                            TheBackupAgent bckupAgent = new TheBackupAgent();
                            bckupAgent.requestBackup();
}


buttonRestore.setOnClickListener(new Button.OnClickListener()
                    {
                        public void onClick(View v) 
                        {
                            TheBackupAgent bckupAgent = new TheBackupAgent();
                            bckupAgent.restoreData();
}

崩溃报告

11-27 11:08:58.463: E/AndroidRuntime(16281): FATAL EXCEPTION: main
11-27 11:08:58.463: E/AndroidRuntime(16281): java.lang.IllegalArgumentException: Package  not found
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.os.Parcel.readException(Parcel.java:1429)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.os.Parcel.readException(Parcel.java:1379)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.app.backup.IBackupManager$Stub$Proxy.beginRestoreSession(IBackupManager.java:852)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.app.backup.BackupManager.requestRestore(BackupManager.java:146)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at in.plackal.lovecyclesfree.TheBackupAgent.restoreData(TheBackupAgent.java:33)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at in.plackal.lovecyclesfree.BackupActivity$1$4.onClick(BackupActivity.java:338)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.view.View.performClick(View.java:4261)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.view.View$PerformClick.run(View.java:17356)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.os.Handler.handleCallback(Handler.java:615)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.os.Handler.dispatchMessage(Handler.java:92)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.os.Looper.loop(Looper.java:137)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at android.app.ActivityThread.main(ActivityThread.java:4921)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at java.lang.reflect.Method.invokeNative(Native Method)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at java.lang.reflect.Method.invoke(Method.java:511)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
11-27 11:08:58.463: E/AndroidRuntime(16281):    at dalvik.system.NativeStart.main(Native Method)