Android App中使用ListFragment的实例教程

2019-12-12 06:24:54

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ListFragment继承于Fragment。因此它具有Fragment的特性，能够作为activity中的一部分，目的也是为了使页面设计更加灵活。
相比Fragment，ListFragment的内容是以列表(list)的形式显示的。ListFragment的布局默认包含一个ListView。因此，在ListFragment对应的布局文件中，必须指定一个 android:id 为 “@android:id/list” 的ListView控件!

ListFragment基础使用
下面介绍在Activity中显示ListFragment的步骤。

1. Activity对应的代码

public class FragmentTest extends Activity { @Override public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.main); } }

2. Activity对应的布局

<LinearLayout 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:orientation="horizontal" > <fragment   android:name="com.skw.fragmenttest.MyListFragment"  android:id="@+id/myfragment"  android:layout_width="match_parent"  android:layout_height="match_parent" /></LinearLayout>

说明：该Activity的布局中只包行了一个Fragment。下面看看MyListFragment的内容。

3. MyListFragment的内容

public class MyListFragment extends ListFragment { private static final String TAG = "##MyListFragment##"; private ListView selfList; String[] cities = {   "Shenzhen",   "Beijing",   "Shanghai",   "Guangzhou",   "Wuhan",   "Tianjing",   "Changsha",   "Xi'an",   "Chongqing",   "Guilin", }; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,    Bundle savedInstanceState) {  Log.d(TAG, "onCreateView");  return inflater.inflate(R.layout.list_fragment, container, false); } @Override public void onCreate(Bundle savedInstanceState) {  Log.d(TAG, "onCreate");  super.onCreate(savedInstanceState);  // 设置ListFragment默认的ListView，即@id/android:list  this.setListAdapter(new ArrayAdapter<String>(getActivity(),     android.R.layout.simple_list_item_1, cities)); } public void onListItemClick(ListView parent, View v,    int position, long id) {  Log.d(TAG, "onListItemClick");  Toast.makeText(getActivity(), "You have selected " + cities[position],    Toast.LENGTH_SHORT).show(); } }

说明：MyListFragment是自定义的ListFragment。它使用了list_fragment.xml作为布局，并通过android.R.layout.simple_list_item_1显示ListView中的每一项。

4. list_fragment.xml的内容

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <!-- ListFragment对应的android:id值固定为"@id/android:list" --> <ListView  android:id="@id/android:list"  android:layout_width="match_parent"  android:layout_height="match_parent"   android:drawSelectorOnTop="false"  /></LinearLayout>

"Activity的布局以及代码"和前面一样，这里就不再重复说明。

5. MyListFragment的内容

public class MyListFragment extends ListFragment { private static final String TAG = "##MyListFragment##"; private ListView selfList; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,    Bundle savedInstanceState) {  Log.d(TAG, "onCreateView");  return inflater.inflate(R.layout.list_fragment, container, false); } @Override public void onCreate(Bundle savedInstanceState) {  final String[] from = new String[] {"title", "info"};  final int[] to = new int[] {R.id.text1, R.id.text2};  Log.d(TAG, "onCreate");  super.onCreate(savedInstanceState);  // 建立SimpleAdapter，将from和to对应起来  SimpleAdapter adapter = new SimpleAdapter(    this.getActivity(), getSimpleData(),     R.layout.item, from, to);  this.setListAdapter(adapter); } public void onListItemClick(ListView parent, View v,    int position, long id) {  Log.d(TAG, "onListItemClick");  Toast.makeText(getActivity(),     "You have selected " + position,    Toast.LENGTH_SHORT).show(); } private List<Map<String, Object>> getSimpleData() {  List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();  Map<String, Object> map = new HashMap<String, Object>();  map.put("title", "Ferris wheel");  map.put("info", "Suzhou Ferris wheel");  list.add(map);  map = new HashMap<String, Object>();  map.put("title", "Flower");  map.put("info", "Roser");  list.add(map);  map = new HashMap<String, Object>();  map.put("title", "Disk");  map.put("info", "Song Disk");  list.add(map);  return list; }}

说明：MyListFragment使用了R.layout.list_fragment作为布局，并且对于ListView中的每一项都使用了R.layout.item作为布局。

6. list_fragment.xml的内容

<ListView
    android:id="@id/android:list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:drawSelectorOnTop="false"
    />

7. item.xml的内容

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView android:id="@+id/text1"  android:textSize="12sp"  android:textStyle="bold"  android:layout_width="match_parent"  android:layout_height="wrap_content"/> <TextView android:id="@+id/text2"  android:textSize="24sp"  android:layout_width="match_parent"  android:layout_height="wrap_content"/></LinearLayout>

ListFragment实例
应用实例说明：建立一个activity，包括2个ListFragment。第1个ListFragment采用中ListView每一行的内容通过android自带的android.R.layout.simple_list_item_1布局来显示；第2个ListFragment每一行的内容通过自定义的layout文件来显示，每一行显示两个文本。

activity对应的layout文件代码：

<LinearLayout 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:orientation="horizontal" > <fragment   android:name="com.skywang.app.ListFragmentImpl"  android:id="@+id/fragment1"   android:layout_weight="1"  android:layout_width="match_parent"  android:layout_height="match_parent" /> <fragment   android:name="com.skywang.app.ListFragmentSelf"  android:id="@+id/fragment2"   android:layout_weight="1"  android:layout_width="match_parent"  android:layout_height="match_parent" /></LinearLayout>

说明：
(01) 该layout布局包含两个fragment。
activity的代码：

package com.skywang.app;import android.os.Bundle;import android.app.Activity;import android.app.FragmentManager;import android.app.FragmentTransaction;import android.view.Menu;public class ListFragmentTest extends Activity { @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.list_fragment_test);   }}

说明：
(01) 在 onCreateView()中，调用list_fragment_impl作为该ListFragment的布局文件。
(02) 在 onCreate()中，通过setListAdapter() 设置android.R.layout.simple_list_item_1为ListView每一行的布局文件，设置cities为其中数据的每一项内容。

ListFragmentImpl.java的代码：

package com.skywang.app;import android.app.ListFragment;import android.widget.ListView; import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.util.Log;import android.widget.Toast;import android.widget.SimpleAdapter;import java.util.Map;import java.util.HashMap;import java.util.List;import java.util.ArrayList;public class ListFragmentImpl extends ListFragment{ private static final String TAG = "ListFragmentImpl";  private ListView selfList;  String[] cities = {   "Shenzhen",   "Beijing",   "Shanghai",   "Guangzhou",   "Wuhan",   "Tianjing",   "Changsha",   "Xi'an",   "Chongqing",   "Guilin", }; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,    Bundle savedInstanceState) {  Log.d(TAG, "onCreateView");  return inflater.inflate(R.layout.list_fragment_impl, container, false); }  @Override public void onCreate(Bundle savedInstanceState) {  Log.d(TAG, "onCreate");  super.onCreate(savedInstanceState);  // 设置ListFragment默认的ListView，即@id/android:list  this.setListAdapter(new ArrayAdapter<String>(getActivity(),     android.R.layout.simple_list_item_1, cities));   }  public void onListItemClick(ListView parent, View v,    int position, long id) {  Log.d(TAG, "onListItemClick");  Toast.makeText(getActivity(),     "You have selected " + cities[position],    Toast.LENGTH_SHORT).show(); } }

list_fragment_impl.xml的内容：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" >  <!-- ListFragment对应的android:id值固定为"@id/android:list" --> <ListView  android:id="@id/android:list"  android:layout_width="match_parent"  android:layout_height="match_parent"   android:drawSelectorOnTop="false"  /> </LinearLayout>

ListFragmentSelf.java的代码：

package com.skywang.app;

import android.app.ListFragment;import android.widget.ListView; import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.util.Log;import android.widget.Toast;import android.widget.SimpleAdapter;import java.util.Map;import java.util.HashMap;import java.util.List;import java.util.ArrayList;public class ListFragmentSelf extends ListFragment{ private static final String TAG = "ListFragmentImpl";  private ListView selfList;  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,    Bundle savedInstanceState) {  Log.d(TAG, "onCreateView");  return inflater.inflate(R.layout.list_fragment_self, container, false); }  @Override public void onCreate(Bundle savedInstanceState) {  final String[] from = new String[] {"title", "info"};  final int[] to = new int[] {R.id.text1, R.id.text2};    Log.d(TAG, "onCreate");  super.onCreate(savedInstanceState);  // 建立SimpleAdapter，将from和to对应起来  SimpleAdapter adapter = new SimpleAdapter(    this.getActivity(), getSimpleData(),     R.layout.two_textview, from, to);  this.setListAdapter(adapter); }  public void onListItemClick(ListView parent, View v,    int position, long id) {  Log.d(TAG, "onListItemClick");  Toast.makeText(getActivity(),     "You have selected " + position,    Toast.LENGTH_SHORT).show(); }  private List<Map<String, Object>> getSimpleData() {  List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();    Map<String, Object> map = new HashMap<String, Object>();  map.put("title", "Ferris wheel");  map.put("info", "Suzhou Ferris wheel");  list.add(map);  map = new HashMap<String, Object>();  map.put("title", "Flower");  map.put("info", "Roser");  list.add(map);  map = new HashMap<String, Object>();  map.put("title", "Disk");  map.put("info", "Song Disk");  list.add(map);    return list; }}

说明：

(01) 在 onCreateView()中，调用list_fragment_self作为该ListFragment的布局文件。
(02) 在 onCreate()中，通过setListAdapter() 设置R.layout.two_textview为ListView每一行的布局文件。

list_fragment_self.xml的内容：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" >  <!-- ListFragment对应的android:id值固定为"@id/android:list" --> <ListView  android:id="@id/android:list"  android:layout_width="match_parent"  android:layout_height="match_parent"   android:drawSelectorOnTop="false"  /> </LinearLayout>

two_textview.xml的内容:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" >  <TextView android:id="@+id/text1"  android:textSize="12sp"  android:textStyle="bold"  android:layout_width="match_parent"  android:layout_height="wrap_content"/> <TextView android:id="@+id/text2"  android:textSize="24sp"  android:layout_width="match_parent"  android:layout_height="wrap_content"/>  </LinearLayout>

效果图：

2016511110549079.png (400×683)