Calling Custom ListView Adapter from Fragment Class Main Activity

21,355

Instead of listViewAdapter = new ListView_Adapter(this);, you should instead try listViewAdapter = new ListView_Adapter(getActivity().getBaseContext());

The Issue is that you are passing a Fragment to the constructor, and not an Activity context.

Share:
21,355
KeorynDeTar
Author by

KeorynDeTar

Updated on August 01, 2022

Comments

  • KeorynDeTar
    KeorynDeTar almost 2 years

    I've written a few listView activities, as a proof of concept for myself that I could do it. Now, I'm having trouble loading a listView activity into a single tab for an app with multiple tabs, that allows both swiping and tab selection for navigation. I get the error "The constructor ListView_Adapter(MainActivity.DummySectionFragment) is undefined" when I try to write the code for it. I'm a beginner, and I've lurked pretty hard here for the past few days. Any help is appreciated.

    TL;DR : I'm a n00b, and I can't figure out this problem.

    My Custom List Adapter

        import android.content.Context;
        import android.view.LayoutInflater;
        import android.view.View;
        import android.view.ViewGroup;
        import android.widget.ArrayAdapter;
        import android.widget.TextView;
    
        public class CustomListViewAdapter extends ArrayAdapter<String> {
    
            public CustomListViewAdapter (Context c) {
                super(c, R.layout.list_cell);
            }
    
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                View row = convertView;
                ListView_Text holder = null;
    
                if (row == null)
                {
                    LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    
                    row = inflater.inflate(R.layout.list_cell, parent, false);
                    holder = new ListView_Text(row);
                    row.setTag(holder);
                }
                else
                {
                    holder = (ListView_Text) row.getTag();
                }
    
                holder.populateFrom(getItem(position));
    
                return row;
            }
    
            static class ListView_Text {
                private TextView cell_name = null;
    
                ListView_Text(View row) {
                    cell_name = (TextView) row.findViewById(R.id.list_cell_name);
                }
    
                void populateFrom(String index) {
                    cell_name.setText(index);
                }
    
            }
        }
    

    My Main Activity

        import java.util.Locale;
    
        import android.app.ActionBar;
        import android.app.ActionBar.Tab;
        import android.app.FragmentTransaction;
        import com.example.twigglebeta2.ListView_Adapter;
        import android.os.Bundle;
        import android.support.v4.app.Fragment;
        import android.support.v4.app.FragmentActivity;
        import android.support.v4.app.FragmentManager;
        import android.support.v4.app.FragmentPagerAdapter;
        import android.support.v4.app.NavUtils;
        import android.support.v4.view.ViewPager;
        import android.view.Gravity;
        import android.view.LayoutInflater;
        import android.view.Menu;
        import android.view.MenuItem;
        import android.view.View;
        import android.view.ViewGroup;
        import android.widget.ListView;
        import android.widget.TextView;
    
        public class MainActivity extends FragmentActivity implements ActionBar.TabListener {
            private static ListView_Adapter listViewAdapter;
            private ListView listView;
    
            SectionsPagerAdapter mSectionsPagerAdapter;
    
            ViewPager mViewPager;
    
            @Override
            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_main);
    
                // Set up the action bar.
                final ActionBar actionBar = getActionBar();
                actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
    
                // Create adapter
                mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
                // Set up the ViewPager with the sections adapter.
                mViewPager = (ViewPager) findViewById(R.id.pager);
                mViewPager.setAdapter(mSectionsPagerAdapter);
    
                // Switch tab selection to match current page when swiped
                mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                            @Override
                            public void onPageSelected(int position) {
                                actionBar.setSelectedNavigationItem(position);
                            }
                        });
    
                // Create a tab for each 'count' in the activity from getCount()
                for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
                    Tab thisTab = actionBar.newTab();
                    thisTab.setText(mSectionsPagerAdapter.getPageTitle(i));
                    thisTab.setTabListener(this);
                    actionBar.addTab(thisTab);
                }
            }
    
            @Override
            public boolean onCreateOptionsMenu(Menu menu) {
                // Inflate the menu; this adds items to the action bar if it is present.
                getMenuInflater().inflate(R.menu.main, menu);
                return true;
            }
    
            @Override
            public void onTabSelected(ActionBar.Tab tab,FragmentTransaction fragmentTransaction) {
                // When the given tab is selected, switch to the corresponding page in
                // the ViewPager.
                mViewPager.setCurrentItem(tab.getPosition());
            }
    
            @Override
            public void onTabUnselected(ActionBar.Tab tab,FragmentTransaction fragmentTransaction) {
            }
    
            @Override
            public void onTabReselected(ActionBar.Tab tab,FragmentTransaction fragmentTransaction) {
            }
    
            /**
             * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
             * one of the sections/tabs/pages.
             */
            public class SectionsPagerAdapter extends FragmentPagerAdapter {
    
                public SectionsPagerAdapter(FragmentManager fm) {
                    super(fm);
                }
    
                @Override
                public Fragment getItem(int position) {
                    // getItem is called to instantiate the fragment for the given page.
                    // Return a DummySectionFragment (defined as a static inner class
                    // below) with the page number as its lone argument.
                    Fragment fragment = new DummySectionFragment();
                    Bundle args = new Bundle();
                    args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
                    fragment.setArguments(args);
                    return fragment;
                }
    
                @Override
                public int getCount() {
                    // Show 3 total pages.
                    return 3;
                }
    
                @Override
                public CharSequence getPageTitle(int position) {
                    Locale l = Locale.getDefault();
                    switch (position) {
                    case 0:
                        return getString(R.string.title_section1).toUpperCase(l);
                    case 1:
                        return getString(R.string.title_section2).toUpperCase(l);
                    case 2:
                        return getString(R.string.title_section3).toUpperCase(l);
                    }
                    return null;
                }
            }
    
            /**
             * A dummy fragment representing a section of the app, but that simply
             * displays dummy text.
             */
            public static class DummySectionFragment extends Fragment {
                /**
                 * The fragment argument representing the section number for this
                 * fragment.
                 */
                public static final String ARG_SECTION_NUMBER = "section_number";
    
                public DummySectionFragment() {
                }
    
                @Override
                public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
                    View rootView = inflater.inflate(R.layout.fragment_main_dummy,container, false);
                    switch(getArguments().getInt(ARG_SECTION_NUMBER)){
                    case 1:
                        //The constructor ListView_Adapter(MainActivity.DummySectionFragment) is undefined
                        listViewAdapter = new ListView_Adapter(this);
                        ListView listView = (ListView) rootView.findViewById(R.id.listView1);
                        for (int i=0;i<20;i++)
                        {
                            listViewAdapter.add("this Index : "+i);
                        }
                        return listView;
                    }
                    TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
                    dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
                    return rootView;
                }
            }
    
        }