无法解析构造函数 ArrayAdapter

Question

我在OnCreateView 方法中使用listAdapter 得到一个Cannot resolve constructor ArrayAdapter 我试图在我的选项卡中列出文本数据，这是我的主要活动。任何帮助将不胜感激，我仍然是 Java 的菜鸟。

public class MainActivity extends ActionBarActivity {

    private Toolbar toolbar;
    private ViewPager mPager;
    private SlidingTabLayout mTabs;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        toolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(toolbar);

        mPager= (ViewPager) findViewById(R.id.viewPager);
        mTabs=(SlidingTabLayout) findViewById(R.id.tabs);
        mPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
        mTabs.setDistributeEvenly(true);
        mTabs.setBackgroundColor(getResources().getColor(R.color.colorPrimary));
        mTabs.setSelectedIndicatorColors(getResources().getColor(R.color.colorAccent));
        mTabs.setViewPager(mPager);
    }

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

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    class MyPagerAdapter extends FragmentPagerAdapter {

        String[] tabs;

        public MyPagerAdapter(FragmentManager fm) {
            super(fm);
            tabs=getResources().getStringArray(R.array.tabs);
        }

        @Override
        public Fragment getItem(int position) {

            MyFragment myFragment=MyFragment.getInstance(position);
            return myFragment;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return tabs[position];
        }

        @Override
        public int getCount() {
            return 5;
        }
    }

    public static class MyFragment extends Fragment {

        private TextView textView;
        private ListView mainListView;
        private ArrayAdapter<String> listAdapter ;

        public static MyFragment getInstance(int position){

            MyFragment myFragment=new MyFragment();
            Bundle  args=new Bundle();
            args.putInt("position", position);
            myFragment.setArguments(args);
            return myFragment;
        }

        @Override

        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

            View layout=inflater.inflate(R.layout.fragment_my, container, false);

            mainListView=(ListView) layout.findViewById(R.id.position);

            String[] planets = new String[] { "Mercury", "Venus", "Earth", "Mars",
                    "Jupiter", "Saturn", "Uranus", "Neptune"};
            ArrayList<String> planetList = new ArrayList<String>();
            planetList.addAll( Arrays.asList(planets) );

            listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);
            mainListView.setAdapter( listAdapter );
            return layout;
        }
    }
}

Answer 1

改变

 listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);

到

 listAdapter = new ArrayAdapter<String>(getActivity(), R.layout.simplerow, planetList);

您可以使用getActivity()在Fragment中获取Context。

Answer 2

将this 替换为activityName.this 改变

listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, planetList);

与

listAdapter = new ArrayAdapter<String>(activityName.this, R.layout.simplerow, planetList);

这解决了我在 asyncTask 中使用的问题。

Answer 3

试试

import android.widget.ArrayAdapter;

这样也能解决问题。