Как добавить фрагмент listview в этот код?

Question

Как добавить фрагмент представления пользовательского списка в этот код, чтобы он отображался под одной из вкладок на панели просмотра?

Я пытаюсь получить его, чтобы он также отображал изображение, у меня есть собственный XML-файл с макетом просмотра списка, но у меня возникают проблемы, пытаясь попасть в один из фрагментов с вкладками.

Вот мой код.

MainActivity.java

import java.util.ArrayList; 
import java.util.List; 
import java.util.Locale; 

import android.support.v7.app.ActionBarActivity; 
import android.support.v7.app.ActionBar; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentTransaction; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.os.Bundle; 
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.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.ImageView; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 


public class MainActivity extends ActionBarActivity implements ActionBar.TabListener { 
    private List<Posts> myPosts = new ArrayList<Posts>(); 
    /** 
    * The {@link android.support.v4.view.PagerAdapter} that will provide 
    * fragments for each of the sections. We use a 
    * {@link FragmentPagerAdapter} derivative, which will keep every 
    * loaded fragment in memory. If this becomes too memory intensive, it 
    * may be best to switch to a 
    * {@link android.support.v4.app.FragmentStatePagerAdapter}. 
    */ 
    SectionsPagerAdapter mSectionsPagerAdapter; 

    /** 
    * The {@link ViewPager} that will host the section contents. 
    */ 
    ViewPager mViewPager; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     populatePostList(); 
     populateListView(); 
     // Set up the action bar. 
     final ActionBar actionBar = getSupportActionBar(); 
     actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 

     // Create the adapter that will return a fragment for each of the three 
     // primary sections of the activity. 
     mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); 

     // Set up the ViewPager with the sections adapter. 
     mViewPager = (ViewPager) findViewById(R.id.pager); 
     mViewPager.setAdapter(mSectionsPagerAdapter); 

     // When swiping between different sections, select the corresponding 
     // tab. We can also use ActionBar.Tab#select() to do this if we have 
     // a reference to the Tab. 
     mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { 
      @Override 
      public void onPageSelected(int position) { 
       actionBar.setSelectedNavigationItem(position); 
      } 
     }); 

     // For each of the sections in the app, add a tab to the action bar. 
     for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) { 
      // Create a tab with text corresponding to the page title defined by 
      // the adapter. Also specify this Activity object, which implements 
      // the TabListener interface, as the callback (listener) for when 
      // this tab is selected. 
      actionBar.addTab(
        actionBar.newTab() 
          .setText(mSectionsPagerAdapter.getPageTitle(i)) 
          .setTabListener(this)); 
     } 
    } 


    @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); 
    } 

    @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. 
    */ 
    private void populatePostList()  { 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 
     myPosts.add(new Posts("Ottawa, Ontario", "787", "Picture of my Dog!", R.drawable.dog)); 



    } 

    private void populateListView() { 
     ArrayAdapter<Posts> adapter = new MyListAdapter(); 
     ListView list = (ListView) findViewById(android.R.id.list); 
     list.setAdapter(adapter); 

    } 
    private class MyListAdapter extends ArrayAdapter<Posts> { 
     public MyListAdapter() { 
      super(MainActivity.this, R.layout.item_view, myPosts); 
     } 


     @Override 
     public View getView(int position, View convertView, ViewGroup parent) { 
      // Make sure we have a view to work with {may have given null} 
      View itemView = convertView; 
      if (itemView == null) { 
       itemView = getLayoutInflater().inflate(R.layout.item_view, parent, false); 
      } 
      // Find the post to work with. 
      Posts currentPost = myPosts.get(position); 


      //Fill the view 
      ImageView imageView = (ImageView) itemView.findViewById(R.id.item_postImage); 
      imageView.setImageResource(currentPost.getIconID()); 

      //Fill in Title 

      TextView titleText = (TextView) itemView.findViewById(R.id.item_postText); 
      //titleText.setText(currentPost.getPosttitle()); 

      //Set Vote Number 
      TextView voteText = (TextView) itemView.findViewById(R.id.item_postVoteText); 
      voteText.setText(currentPost.getPostvote()); 


      return itemView; 
     } 
    } 
    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 PlaceholderFragment (defined as a static inner class below). 
      switch (position){ 
       case 0: 
        return new TheWallFragment(); 
       case 1: 
        return new TheWallFragment(); 
       case 2: 
        return new TheWallFragment(); 
       default: 
        break; 

      } 
      return PlaceholderFragment.newInstance(position + 1); 
     } 

     @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 placeholder fragment containing a simple view. 
    */ 
    public static class PlaceholderFragment extends Fragment { 
     /** 
     * The fragment argument representing the section number for this 
     * fragment. 
     */ 
     private static final String ARG_SECTION_NUMBER = "section_number"; 

     /** 
     * Returns a new instance of this fragment for the given section 
     * number. 
     */ 
     public static PlaceholderFragment newInstance(int sectionNumber) { 
      PlaceholderFragment fragment = new PlaceholderFragment(); 
      Bundle args = new Bundle(); 
      args.putInt(ARG_SECTION_NUMBER, sectionNumber); 
      fragment.setArguments(args); 
      return fragment; 
     } 

     public PlaceholderFragment() { 
     } 

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

} 

activity_main.xml

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/pager" 
    android:layout_width="match_parent" android:layout_height="match_parent" 
    tools:context=".MainActivity" /> 

fragment_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" 
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    tools:context=".MainActivity$PlaceholderFragment"> 

    <TextView android:id="@+id/section_label" android:layout_width="wrap_content" 
     android:layout_height="wrap_content" /> 

</RelativeLayout> 

TheWallFragment

public class TheWallFragment extends android.support.v4.app.ListFragment { 


    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     return inflater.inflate(R.layout.wall_layout, container, false); 
    } 



} 

Answer 1

Класс SectionsPagerAdapter является то, что говорит ViewPager, который идет фрагмент, где. Его метод getCount() возвращает «3», поэтому ViewPager имеет три страницы. Метод getItem() возвращает нужный фрагмент для страницы по адресу position. Поэтому, если вы хотите, чтобы ваш фрагмент просмотра списка появился на первой странице, вы должны создать этот фрагмент в getItem() и вернуть его, когда position == 0.

@Override 
    public Fragment getItem(int position) { 
     // getItem is called to instantiate the fragment for the given page. 
     switch (position) { 
      case 0: 
       return new ListFragment(); 
      case 1: 
       return new SecondFragment(); 
      case 2: 
       return new ThirdFragment(); 
     } 
    }