包含ListView不會填充

Question

我想在另一個視圖中包含一個列表片段，但列表似乎沒有填充。 Android Studio中的設計視圖顯示包含了listView，但是當構建項目時，我所看到的只是一個未填充的主要活動。

我希望有人能告訴我爲什麼這樣。

ListFragment類：

package com.starlineeducation.starlinemobile; 

import android.app.ListFragment; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.ListView; 
import android.widget.Toast; 

public class ListActivityFragment extends ListFragment { 

    static final String[] CLASSES = 
      new String[] { "Government", "Hawaiian History", "Economics", "Psychology"}; 


    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setListAdapter(new ClassAdapter(getActivity(), CLASSES)); 
    } 
    @Override 
    public void onListItemClick(ListView l, View v, int position, long id) { 

     String selectedValue = (String) getListAdapter().getItem(position); 
     Toast.makeText(getActivity(), selectedValue, Toast.LENGTH_SHORT).show(); 

    } 
} 

定製適配器類：

package com.starlineeducation.starlinemobile; 

import android.content.Context; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class ClassAdapter extends ArrayAdapter<String> { 
    private final Context context; 
    private final String[] values; 

    public ClassAdapter(Context context, String[] values) { 
     super(context, R.layout.listitem_classes, values); 
     this.context = context; 
     this.values = values; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     LayoutInflater inflater = (LayoutInflater) context 
       .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

     View rowView = inflater.inflate(R.layout.listitem_classes, parent, false); 
     TextView textView = (TextView) rowView.findViewById(R.id.label); 
     ImageView imageView = (ImageView) rowView.findViewById(R.id.logo); 
     textView.setText(values[position]); 

     // Change icon based on name 
     String s = values[position]; 

     if (s.equals("Psychology")) { 
      imageView.setImageResource(R.drawable.ic_psychology); 
     } else if (s.equals("Government")) { 
      imageView.setImageResource(R.drawable.ic_government); 
     } else if (s.equals("Hawaiian History")) { 
      imageView.setImageResource(R.drawable.ic_hawaiian_history); 
     } else if (s.equals("Economics")){ 
      imageView.setImageResource(R.drawable.ic_economics); 
     } 

     return rowView; 
    } 
} 

MainActivity XML：

<?xml version="1.0" encoding="utf-8"?> 
    <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true" 
    tools:context="com.starlineeducation.starlinemobile.MainActivity"> 

    <android.support.design.widget.AppBarLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:theme="@style/AppTheme.AppBarOverlay" 
     app:elevation="0dp"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      android:background="?attr/colorPrimary" 
      app:popupTheme="@style/AppTheme.PopupOverlay" /> 

    </android.support.design.widget.AppBarLayout> 

    <include layout="@layout/listview_classes" /> 

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/fab" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_gravity="bottom|end" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@drawable/ic_new_class" /> 

</android.support.design.widget.CoordinatorLayout> 

的ListView XML（listview_classes.xml）：

<?xml version="1.0" encoding="utf-8"?> 
    <ListView 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:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context=".ListActivityFragment" 
    tools:listitem="@layout/listitem_classes" 
    tools:showIn="@layout/activity_main"> 

</ListView> 

Answer 1

你ListActivityFragment應該是這樣的（添加onCreateView()，覆蓋onActivityCreated()代替onCreate()，並設置項目點擊收聽）：

public class ListActivityFragment extends ListFragment implements OnItemClickListener{ 

    static final String[] CLASSES = { "Government", "Hawaiian History", "Economics", "Psychology"}; 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     View view = inflater.inflate(R.layout.main_layout, container, false); 

     return view; 
    } 

    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
     super.onActivityCreated(savedInstanceState); 

     setListAdapter(new ClassAdapter(getActivity(), CLASSES)); 
     getListView().setOnItemClickListener(this); 

    } 

    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
     // do dome thing with 'position'. 
    } 
}