如何添加一個listview片段到這段代碼？

Question

如何將自定義列表視圖片段添加到此代碼中，以便它顯示在視圖分頁器的其中一個選項卡下？

我想獲得它，所以它也顯示圖片，我有一個適當的xml文件與列表視圖佈局，但我有麻煩試圖讓它進入一個選項卡片段。

這是我的代碼。

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中

<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

類SectionsPagerAdapter就是告訴這些片段去哪裏了ViewPager。它的getCount()方法返回'3'，所以ViewPager有三個頁面。 getItem()方法在position處返回您想要的頁面片段。因此，如果您希望列表視圖片段出現在第一頁上，則必須在getItem()中創建該片段，並在position == 0時將其返回。

@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(); 
     } 
    }