Question

她是我的代码

 public static class DetailFragment extends Fragment {
        private String forecastData;

        private static final String LOG_TAG = DetailFragment.class.getSimpleName();

        private static final String FORECAST_SHARE_HASHTAG ="#SunshineApp";

        public DetailFragment() {

        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setHasOptionsMenu(true);

        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
           View rootView = inflater.inflate(R.layout.fragment_detail, container, false);
            //receive forecast data from the ForeCast Fragment
            Intent intent=getActivity().getIntent();
            forecastData=intent.getStringExtra(Intent.EXTRA_TEXT);
            Log.v(LOG_TAG,"data is "+forecastData);
            TextView textView=(TextView)rootView.findViewById(R.id.detail_text);
            textView.setText(forecastData);

            return rootView;
        }

        @Override
        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
            super.onCreateOptionsMenu(menu, inflater);
            inflater.inflate(R.menu.menu_detailfragment,menu);

            MenuItem menuItem=menu.findItem(R.id.action_share);
            // Get the provider and hold onto it to set/change the share intent.
            ShareActionProvider mShareActionProvider =
                     (ShareActionProvider) MenuItemCompat.getActionProvider(menuItem);

            // Attach an intent to this ShareActionProvider.  You can update this at any time,
            // like when the user selects a new piece of data they might like to share.
            if (mShareActionProvider!= null ) {
                mShareActionProvider.setShareIntent(createShareIntent());

            }
            else
            {
                Log.v(LOG_TAG,"Share Action Provider is null");
            }
        }
        public  Intent createShareIntent()
        {
            Log.v(LOG_TAG,"data is "+forecastData);
            Intent intent=new Intent(Intent.ACTION_SEND);
            intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
            intent.setType("text/plain");
            intent.putExtra(Intent.EXTRA_TEXT,forecastData+DetailFragment.FORECAST_SHARE_HASHTAG);
            Log.v(LOG_TAG,"data is "+forecastData);
            return  intent;
        }

我绝对相信这个意图是正确的，因为我可以与其他应用分享它并且有效，如果你看到下面的日志，那就很清楚

01-04 18:36:02.370    6121-6121/com.example.droid.sunshine V/DetailFragment﹕ in optionMenu method data is null
01-04 18:36:02.380    6121-6121/com.example.droid.sunshine V/DetailFragment﹕ in create intent data is null
01-04 18:36:02.380    6121-6121/com.example.droid.sunshine V/DetailFragment﹕ in create intent data is null
01-04 18:36:02.650    6121-6121/com.example.droid.sunshine V/DetailFragment﹕ in view method data is Wed, Jan 7 - Clear - 27/24

为什么这样，我认为在OnCreateOptionsMenu（）之前调用了OnCreate（）视图方法？我该怎么做才能纠正这个问题？

Answer 1

这是一个想法：

根据您的日志，输出首先显示在onCreateOptionsMenu()方法中，而最后一个输出来自onCreateView()。这意味着在onCreateOptionsMenu()之前调用onCreateView，这可以解释为什么一切都为空。
尝试在其他地方移动setHasOptionsMenu(true)，也许在构造函数中移动{应用}确保onCreateOptionsMenu()和onCreate之后调用onCreateView。试试吧。

Answer 2

你应该把代码从onCreateView（）移到onActvivityCreated（）。

onCreateView旨在返回视图。

onActivityCreated表示关联的活动已完成其onCreate（）方法并已设置。

无法理解为什么字符串值突然变为null？

2 个答案: