关于ListFragment的基本写法及注意事项

关于ListFragment的基本写法及注意事项

    ListFragment是Fragment的子类，一般我们用ListFragment的时候都是先继承ListFragment重写我们自己的Fragment1、Fragment2。

重写ListFragment的时候特别注意，它有两个重要的方法：

1、onCreateView（）；
2、onCreate（）;
格式代码：（以下是代码实例）
我们要写的是一个这样的例子，如下图

首先我们需要写一个总的activity界面，来包含两个ListFragment（Fragment1、Fragment2）
Fragment1里的ListView的ListItem布局用的是系统自带，Fragment2用的是自定义的，自定义代码custom.xml在下面有附上

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?><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"    tools:context="com.example.administrator.listfragment.MainActivity">    <fragment        android:name="com.example.administrator.listfragment.Fragment1"        android:id="@+id/fragment1"        android:layout_weight="1"        android:layout_width="match_parent"        android:layout_height="match_parent">    </fragment>    <fragment        android:name="com.example.administrator.listfragment.Fragment2"        android:id="@+id/fragment2"        android:layout_weight="1"        android:layout_width="match_parent"        android:layout_height="match_parent">    </fragment></LinearLayout>

接着就是Fragment1、Fragment2的java代码和xml代码了，
Fragment1.java:

package com.example.administrator.listfragment;import android.app.ListFragment;import android.os.Bundle;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.ListView;/** * Created by Administrator on 2016/3/2. */public class Fragment1 extends ListFragment{    private String[] cities = {"北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳"};    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        return inflater.inflate(R.layout.fragment1,container);    }    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        this.setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_expandable_list_item_1, cities));    }    @Override    public void onListItemClick(ListView l, View v, int position, long id) {        super.onListItemClick(l, v, position, id);        Log.i("tag","左边条目！！！！！！！！！");    }}

fragment1.xml:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"              android:orientation="vertical"              android:layout_width="match_parent"              android:layout_height="match_parent">    <ListView        android:layout_height="match_parent"        android:layout_width="match_parent"        android:id="@id/android:list">    </ListView></LinearLayout>

Fragment2.java:

package com.example.administrator.listfragment;import android.app.ListFragment;import android.os.Bundle;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ListView;import android.widget.SimpleAdapter;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;/** * Created by Administrator on 2016/3/2. */public class Fragment2 extends ListFragment{    private String[] names = {"name","sex"};    private int[] id = {R.id.text, R.id.image};    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        return inflater.inflate(R.layout.fragment2,container);    }    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        this.setListAdapter(new SimpleAdapter(getActivity(),getdatas(),R.layout.custom,names,id));    }    @Override    public void onListItemClick(ListView l, View v, int position, long id) {        super.onListItemClick(l, v, position, id);        Log.i("tag", "！！！！！！！！！！右边条目");    }    private List<Map<String, Object>> getdatas() {        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();        Map<String, Object> map = new HashMap<>();        map.put("name", "aa");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        map = new HashMap<>();        map.put("name", "bb");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        map = new HashMap<>();        map.put("name", "cc");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        map = new HashMap<>();        map.put("name", "dd");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        return list;    }}

fragment2.xml:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"              android:orientation="vertical"              android:layout_width="match_parent"              android:layout_height="match_parent">    <ListView        android:layout_height="match_parent"        android:layout_width="match_parent"        android:id="@id/android:list">    </ListView></LinearLayout>

custom.xml:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"              android:orientation="vertical"              android:layout_width="match_parent"              android:layout_height="match_parent">    <TextView        android:id="@+id/text"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="12sp"/>    <ImageView        android:id="@+id/image"        android:layout_height="30dp"        android:layout_width="30dp"/></LinearLayout>

总的来说代码大概就是这样了，需要注意的是
1、ListView的命名必须是android:id=”@id/android:list”一定要注意，不能更改
2、onCreateView方法是用来加载listview布局
3、onCreate方法是用来加载listview的listitem布局和数据 和 设置适配器
4、onCreate方法中的this表示默认的android:id的listview , this.setListAdapter也是默认的
5、注意ArrayAdapter和SimpleAdapter的使用和区别
ArrayAdapter和SimpleAdapter代码块：

1、new ArrayAdapter<String>(getActivity(), android.R.layout.simple_expandable_list_item_1, cities);private String[] cities = {"北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳","北京", "上海", "广州", "深圳"};2、new SimpleAdapter(getActivity(),getdatas(),R.layout.custom,names,id);private String[] names = {"name","sex"};private int[] id = {R.id.text, R.id.image};private List<Map<String, Object>> getdatas() {        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();        Map<String, Object> map = new HashMap<>();        map.put("name", "aa");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        map = new HashMap<>();        map.put("name", "bb");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        map = new HashMap<>();        map.put("name", "cc");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        map = new HashMap<>();        map.put("name", "dd");        map.put("sex", R.mipmap.ic_launcher);        list.add(map);        return list;    }