Question

确定。我阅读了文档：here和here，无论如何都无法备份我的偏好。我的代码： AndroidManifest：

<application android:allowBackup="true" android:label="@string/app_name"
    android:icon="@mipmap/ic_launcher" android:theme="@style/AppTheme"
    android:backupAgent="TheBackupAgent" android:restoreAnyVersion="true">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
    <meta-data android:name="com.google.android.backup.api_key" android:value="AEdPqrEAAAAIGyGIg_B8K6KrtT06kRX_YljuwtOxzKYHBZ_H0A" />
</application>

我的主要活动：

package com.settings.backup.casper.backupsettings;

public class MainActivity extends Activity{
private EditText txtContainer;
private Button btnSave;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);
    BackupManager bm = new BackupManager(this);
    bm.dataChanged();
    bm.requestRestore(new RestoreObserver() {
        @Override
        public void restoreStarting(int numPackages) {
            super.restoreStarting(numPackages);
        }
    });

    txtContainer = (EditText) findViewById(R.id.txtPreferences);
    btnSave = (Button) findViewById(R.id.btnSave);
    SharedPreferences preferences = getSharedPreferences(TheBackupAgent.PREFS_NAME, MODE_PRIVATE);
    txtContainer.setText(preferences.getString("prf", ""));

    btnSave.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            SharedPreferences preferences = getSharedPreferences(TheBackupAgent.PREFS_NAME, MODE_PRIVATE);
            SharedPreferences.Editor editor = preferences.edit();
            editor.putString("prf", txtContainer.getText().toString());
            editor.commit();
            TheBackupAgent.requestBackup(getBaseContext());
        }
    });
}
}

我的BackupAgentHelper工具：

package com.settings.backup.casper.backupsettings;

 public class TheBackupAgent extends BackupAgentHelper {
// The name of the SharedPreferences file
static final String PREFS_NAME = "myprefs";
// A key to uniquely identify the set of backup data
static final String PREFS_BACKUP_KEY = "myprefs";

@Override
public void onCreate() {
    SharedPreferencesBackupHelper helper = new SharedPreferencesBackupHelper(this, PREFS_NAME);
    addHelper(PREFS_BACKUP_KEY, helper);
    Log.d("Test", "Adding backupagent...");
}

@Override
public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState) throws IOException {
    super.onRestore(data, appVersionCode, newState);
}

@Override
public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data, ParcelFileDescriptor newState) throws IOException {
    super.onBackup(oldState, data, newState);
}

public static void requestBackup(Context context) {
    BackupManager bm = new BackupManager(context);
    bm.dataChanged();
 }
}

我知道android在调用dataChanged（）之后不会立即背包数据;这就是我在android.dev上使用adb shell的原因，但是当我重新安装应用程序时它没有恢复。在手机选项中，我启用备份。我试过3个不同的手机这个代码。有谁知道它为什么不起作用？

备份管理器不工作

0 个答案: