Andorid中相似QQ好友中那樣的雙重列表

一：ExpandableListView  雙重列表，就像QQ好友同樣，點擊好友，就顯示好友的列表

1：主佈局文件：

<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: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=".MainActivity" >

    <ExpandableListView
        android :id="@+id/activity_main_expandablelistview"
        android :layout_width="match_parent"
        android :layout_height="wrap_content" />

</RelativeLayout >

2：父列表佈局文件

<?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="horizontal" >

    <TextView
        android :id="@+id/activity_listview_showtext"
        android :layout_width="wrap_content"
        android :layout_height="wrap_content"
        android :layout_marginLeft="30dp"
        android :textColor="#FF0000"
        android :textSize="30sp"></ TextView>

</LinearLayout >

3：子列表佈局文件

<?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/activity_item_childtext"
        android :layout_width="wrap_content"
        android :layout_height="wrap_content"
        android :textColor="#ff2bfe"
        android :textSize="20sp"></ TextView>

</LinearLayout >

4：Activity

public class MainActivity extends AppCompatActivity {
     public  ExpandableListView mainlistview = null;
     public  List<String> parent=null ;
     public  Map<String, List<String>> map = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super .onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mainlistview = (ExpandableListView) findViewById(R.id.activity_main_expandablelistview );
        initData();
        MyAdapter adapter=new MyAdapter(parent,map,MainActivity. this);
        mainlistview .setAdapter(adapter);
    }

    public void initData() {
        parent = new ArrayList<String>();
        parent .add("parent1");
        parent .add("parent2");
        parent .add("parent3");

        map = new HashMap<String, List<String>>();

        List<String> list1 = new ArrayList<String>();
        list1.add("child1-1");
        list1.add("child1-2");
        list1.add("child1-3");
        map .put("parent1", list1);

        List<String> list2 = new ArrayList<String>();
        list2.add("child2-1");
        list2.add("child2-2");
        list2.add("child2-3");
        map .put("parent2", list2);

        List<String> list3 = new ArrayList<String>();
        list3.add("child3-1");
        list3.add("child3-2");
        list3.add("child3-3");

        map .put("parent3", list3);

    }

}

5：適配器（雙重列表是繼承於BaseExpandableListAdapter ）

public class MyAdapter extends BaseExpandableListAdapter {
    public  List<String> first=new ArrayList<>();
    public Map<String, List<String>> map =new HashMap<String, List<String>>();
    private  Context context;

    public MyAdapter(List<String> first, Map<String, List<String>> map, Context context) {
        this .first =first;
        this .map = map;
        this .context = context;
    }

    //獲得子item須要關聯的數據
    @Override
    public Object getChild(int groupPosition, int childPosition) {
        String key = first.get(groupPosition);
        return (map .get(key).get(childPosition));
    }

    //獲得子item的ID
    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    //設置子item的組件
    @Override
    public View getChildView(int groupPosition, int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        String key =first.get(groupPosition);
        String info = map.get(key).get(childPosition);
        if (convertView == null) {
            convertView=LayoutInflater.from(context).inflate(R.layout. item_childlistview,parent, false);
        }
        TextView tv = (TextView) convertView
                .findViewById(R.id.activity_item_childtext);
        tv.setText(info);
        convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "點擊了子View", Toast.LENGTH_SHORT).show();
            }
        });
        return convertView;
    }

    //獲取當前父item下的子item的個數
    @Override
    public int getChildrenCount(int groupPosition) {
        String key = first.get(groupPosition);
        int size=map.get(key).size();
        return size;
    }
    //獲取當前父item的數據
    @Override
    public Object getGroup(int groupPosition) {
        return first.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return first.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }
    //設置父item組件
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView=LayoutInflater.from(context).inflate(R.layout. item_listview,parent, false);
        }
        TextView tv = (TextView) convertView
                .findViewById(R.id.activity_listview_showtext);
        tv.setText(first.get(groupPosition));
        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return true ;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true ;
    }

}