返回 Activity 后 Android 服务挂起

Question

我觉得这个问题很有趣，有些人可能不感兴趣。希望我能得到可靠的答案。

我有一个 Fragment，它在 onResume() 中绑定(bind)了一个服务，当用户在场时每 60 秒自动刷新一次数据。我的 bind() 方法在这里...

public void bind() {
    if(connected || MainActivity.sRefresherBinding) return;
    MainActivity.sRefresherBinding = true;
    Log.v(LOG_TAG, "binding...");
    mProgressDialog.setTitle("Service Connected!");
    mProgressDialog.setMessage("We're almost there!");
    Intent bindingIntent = new Intent(getActivity(), Refresh.class);
    getActivity().bindService(bindingIntent, mConnection, Context.BIND_AUTO_CREATE);
    getActivity().startService(bindingIntent);
}

这里对应的unbind()方法在onStop()中调用...

public void unbind() {
        Log.v(LOG_TAG, "unbinding");
        if (connected) {
            mRefreshService.terminate();
            getActivity().unbindService(mConnection);
            getActivity().stopService(new Intent(getActivity(), Refresh.class));
            connected = false;
        }
    }

onServiceConnected() 这里...

public void onServiceConnected(ComponentName name, IBinder service) {
        if(binder != null) binder = null;
        binder = (Refresh.LocalBinder) service;
        if(mRefreshService != null) mRefreshService.terminate();
        mRefreshService = binder.getService();
        connected = true;
        mProgressDialog.setTitle("Refreshing your data...");
        mProgressDialog.setMessage("We are almost there!");
        Log.v(LOG_TAG, "Service Connected");
    }

我的 onStartCommand() 刷新扩展服务

public int onStartCommand(Intent intent, int flags, int startId) {
    start(new UpdateListener() {
        @Override
        public void onUpdate(ArrayList<Quote.SingleQuote> newData) {
            Intent broadcastIntent = new Intent();
            broadcastIntent.setAction(Utility.BROADCAST);
            broadcastIntent.putExtra(Utility.QUOTE_INTENT, newData);
            sendBroadcast(broadcastIntent);
        }
    });

    if (mHandler == null) {
        mHandler = new Handler();
        mHandler.post(mRunnable);
    }

    return Service.START_STICKY;
}

可运行的...

private Runnable mRunnable = new Runnable() {
    @Override
    public void run() {
        refreshMain();
        if (mHandler != null)
            mHandler.postDelayed(this, MIN_UPDATE_TIME);
    }
};

refreshMain 太大，我将只发布将结果发送回监听器的 fragment ...

call.enqueue(new Callback<Quote>() {

            @Override
            public void onResponse(Response<Quote> response) {
                try {                        
                    List<Quote.SingleQuote> asList = response.body().query.results.getQuote();
                    mQuotes = new ArrayList<>(asList);
                    mListener.onUpdate(mQuotes);
                    Log.v(LOG_TAG, "Refreshed");

                }

最后是我的广播接收器...

public static class UpdateReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(final Context context, final Intent intent) {

        if(MainFragmentService.getInstance().mProgressDialog != null) MainFragmentService.getInstance().mProgressDialog.dismiss();
        if(MainFragmentService.getInstance() != null) {
            MainFragmentService.getInstance().mQuotes = intent.getParcelableArrayListExtra(Utility.QUOTE_INTENT);
            MainFragmentService.getInstance().mAdapter.swapList(MainFragmentService.getInstance().mQuotes);
            Log.v(LOG_TAG, "Package received");
            MainActivity.sRefresherBinding = false;
        }
    }
}

这是棘手的部分。 所有这些代码在我的 Nexus 5 上运行得很好，但是当我在我的 Nexus 7 上运行它时，进入另一个 Activity 并返回，服务挂起。数据被获取、广播、拾取，但对话框没有被关闭，数据也没有显示在回收站 View 中。

看看我的 Nexus 5 上的 logcat:

V/MainFragmentService: onPause
V/MainFragmentService: unbinding
V/MainFragmentService: onStop
V/MainFragmentService: onResume
V/MainFragmentService: binding...
V/Refresh: RefreshMain called
V/MainFragmentService: Service Connected
V/Refresh: Refreshed
V/MainFragmentService: Package received

现在看看我的 Nexus 7 上的 logcat:

V/MainFragmentService: onPause
V/MainFragmentService: unbinding
V/MainFragmentService: onStop
V/MainFragmentService: onResume
V/MainFragmentService: binding...
V/MainFragmentService: onResume
V/Refresh: RefreshMain called
V/MainFragmentService: Service Connected
V/Refresh: Refreshed
V/MainFragmentService: Package received
V/Refresh: Waiting
V/Refresh: Waiting
V/Refresh: RefreshMain called
V/Refresh: Refreshed
V/MainFragmentService: Package received

如果您对这段代码的工作有任何疑问，该应用程序就在这里，请转到 nuts .如果您通读了这篇文章，感谢您抽出时间!

Answer 1

问题追踪到开发者选项 > 应用程序 > 不要让 Activity 在 Nexus 7 上启用，在 Nexus 5(和其他)上禁用。

这意味着真正的问题出在 Activity 本身上，它在离开 Activity 时被销毁了。返回时，会在现有 fragment 之上创建一个新 fragment ，因为我没有检查 savedInstanceState。上面评论中提到的困惑现在也已修复，无需再通过 Manifest 防止配置更改时的 Activity 破坏。

getFragmentManager().beginTransaction().add(R.id.content_main_list_container,
new MainFragmentService(), FRAGMENT_TAG_MAIN_LIST).commit();

现在是...

MainFragmentService mainFragment;
        if(savedInstanceState == null) {
            mainFragment = new MainFragmentService();
            getFragmentManager()
                    .beginTransaction()
                    .add(R.id.content_main_list_container,
                            mainFragment, FRAGMENT_TAG_MAIN_LIST)
                    .commit();
        }