Question

所以，这是myActivity.java

基本上，当我尝试使用.commit（）时，我在onCreate方法中遇到错误所以，只是不确定为什么会这样。可以使用一些指导。谢谢！

另外，像片段的初学者那样，不时让我感到有些困惑。

它向我显示它“无法解析方法commit（）”。

public class MyActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);
        if (savedInstanceState == null) {
            getFragmentManager().beginTransaction()
                    .add(R.id.container, new ForecastFragment()
                            .commit();

        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.my, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A Forecast fragment containing a simple view.
     */
    public static class ForecastFragment extends Fragment {

        private ArrayAdapter<String> mForecastAdapter;

        public ForecastFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_my, container, false);

            String[] forecastArray={
                    "Right Now - Hot. Grab a Lemonade!",
                    "Today -  Boiling! Feels more like a Heat Furnace!",
                    "Tomorrow - Rains! Carry an Umbrella!",
                    "Tuesday - Hailstones!",
                    "Wednesday - Stormy",
                    "Thursday - Snowfall!",
                    "Friday - Rebecca Black",
                    "Saturday - Thunder!",
                    "Sunday - Just right." };

            List<String>weekForecast=new ArrayList<String>(Arrays.asList(forecastArray));

             mForecastAdapter = new ArrayAdapter<String>(
                    getActivity(),
                    R.layout.list_item_forecast,
                    R.id.list_item_forecast_textview,
                    weekForecast);

            ListView listView=(ListView) rootView.findViewById(R.id.listview_forecast);
            listView.setAdapter(mForecastAdapter);


            return rootView;
        }


    }
}

Answer 1

这是错误的

    if (savedInstanceState == null) {
        getFragmentManager().beginTransaction()
                .add(R.id.container, new ForecastFragment().
                        commit()); //<-----

    }

commit()是FragmentTransaction上的方法，而不是Fragment上的方法。所以将代码更改为：

    if (savedInstanceState == null) {
        getFragmentManager().beginTransaction()
                .add(R.id.container, new ForecastFragment())
                .commit();

    }

Answer 2

如果你对困惑的片段感到困惑，你就不应该把所有这些事情联系起来，在你完全感到舒服的情况下，将它们分开来做：

   getFragmentManager().beginTransaction()
                  .add(R.id.container, new ForecastFragment()
                        .commit();

成为

ForecastFragment newFragment = new ForecastFragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.add(R.id.container, newFragment );
transaction.addToBackStack(null);
transaction.commit();

错误。 onCreate方法中片段中的.commit（）

2 个答案: