Android实战简易教程（树形组件：ExpandableListView显示和动态添加删除）

ListView组件可以为用户提供列表的显示功能，但是如果想对这些列表数据进行分组管理，则需要使用android.widget.ExpandableListView组件完成。

与ListView组件一样，如果想要进行数据显示的设置，也需要一个适配器类，但是此时不再继承之前的BaseAdapter，而是继承BaseExpandableListAdapter类完成，此类为抽象类，所以要实现其中的所有抽象方法。

一、创建ExpandableListView

1.定义适配器类-MyExpandableListAdapter.java

 package org.yayun.demo;

 import android.content.Context;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AbsListView;
 import android.widget.BaseExpandableListAdapter;
 import android.widget.TextView;

 public class MyExpandableListAdapter extends BaseExpandableListAdapter {
     public String[] groupStrings = { "我的好友", "我的家人", "同事", "狐朋狗友" };
     public String[][] childStrings = { { "瓜瓜", "太湖", "老皮", "磨叽" },
             { "大姐", "肥肥", "二姐", "爸爸" }, { "张工", "程序猿" }, { "大鹏", "二妞" } };
     private Context context;

     MyExpandableListAdapter(Context context) {
         this.context = context;
     }

     public int getGroupCount() {// 自动覆写
         return this.groupStrings.length;
     }

     public int getChildrenCount(int groupPosition) {// 自动覆写
         return childStrings[groupPosition].length;
     }

     public Object getGroup(int groupPosition) {// 自动覆写
         return groupStrings[groupPosition];
     }

     public Object getChild(int groupPosition, int childPosition) {// 自动覆写
         return childStrings[groupPosition][childPosition];
     }

     public long getGroupId(int groupPosition) {// 自动覆写
         return groupPosition;
     }

     public long getChildId(int groupPosition, int childPosition) {// 自动覆写
         return childPosition;
     }

     public boolean hasStableIds() {// 自动覆写
         return true;
     }

     public View getGroupView(int groupPosition, boolean isExpanded,
             View convertView, ViewGroup parent) {// 自动覆写
         TextView textView = buildTextView();
         textView.setText(this.getGroup(groupPosition).toString());
         return textView;
     }

     private TextView buildTextView() {
         AbsListView.LayoutParams params = new AbsListView.LayoutParams(
                 ViewGroup.LayoutParams.FILL_PARENT, 35);// 指定布局参数
         TextView textView = new TextView(this.context);// 创建TextView
         textView.setLayoutParams(params);// 设置布局参数
         textView.setTextSize(15.0f);
         textView.setGravity(Gravity.LEFT);// 左对齐
         textView.setPadding(40, 8, 3, 3);// 间距
         return textView;
     }

     public View getChildView(int groupPosition, int childPosition,
             boolean isLastChild, View convertView, ViewGroup parent) {// 自动覆写
         TextView textView = buildTextView();
         textView.setText(getChild(groupPosition, childPosition).toString());
         return textView;
     }

     public boolean isChildSelectable(int groupPosition, int childPosition) {// 自动覆写
         return true;
     }

 }

2.定义布局文件：

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

     <ExpandableListView
         android:id="@+id/elistview"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content" />

 LinearLayout>

3.定义MainActivity.java:

 package org.yayun.demo;

 import android.app.Activity;
 import android.database.DataSetObserver;
 import android.os.Bundle;
 import android.view.ContextMenu;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.widget.ExpandableListAdapter;
 import android.widget.ExpandableListView;
 import android.widget.Toast;
 import android.widget.ExpandableListView.OnChildClickListener;
 import android.widget.ExpandableListView.OnGroupClickListener;
 import android.widget.ExpandableListView.OnGroupCollapseListener;
 import android.widget.ExpandableListView.OnGroupExpandListener;

 public class MainActivity extends Activity {
     private ExpandableListView expandableListView;
     private ExpandableListAdapter adapter;

     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState); // 生命周期方法
         super.setContentView(R.layout.main); // 设置要使用的布局管理器
     expandableListView=(ExpandableListView)findViewById(R.id.elistview);
     adapter=new MyExpandableListAdapter(this);
     expandableListView.setAdapter(adapter);
     super.registerForContextMenu(this.expandableListView);//注册上下文菜单
     /*
      * 下面四个监听是其特有的
      */
     expandableListView.setOnChildClickListener(new OnChildClickListenerImpl());//子项单击事件
     expandableListView.setOnGroupClickListener(new OnGroupClickListenerImpl());//组项单击事件
     expandableListView.setOnGroupCollapseListener(new OnGroupCollapseListenerImpl());//关闭分组事件
     expandableListView.setOnGroupExpandListener(new OnGroupExpandListenerImpl());//展开分组事件

     }
     private class OnChildClickListenerImpl implements OnChildClickListener{

         public boolean onChildClick(ExpandableListView parent, View v,
                 int groupPosition, int childPosition, long id) {
             Toast.makeText(MainActivity.this, "子项被选中，groupPosition="+groupPosition+"childPosition="+childPosition, Toast.LENGTH_SHORT).show();
             return false;
         }

     }
     private class OnGroupClickListenerImpl implements OnGroupClickListener{

         public boolean onGroupClick(ExpandableListView parent, View v,
                 int groupPosition, long id) {
             Toast.makeText(MainActivity.this, "组项被选中，groupPosition="+groupPosition, Toast.LENGTH_SHORT).show();
             return false;
         }

     }
     private class OnGroupCollapseListenerImpl implements OnGroupCollapseListener{

         public void onGroupCollapse(int groupPosition) {
             Toast.makeText(MainActivity.this, "分组关闭，groupPosition="+groupPosition, Toast.LENGTH_SHORT).show();

         }

     }
     private class OnGroupExpandListenerImpl implements OnGroupExpandListener{

         public void onGroupExpand(int groupPosition) {
             Toast.makeText(MainActivity.this, "分组展开，groupPosition="+groupPosition, Toast.LENGTH_SHORT).show();
         }

     }
     @Override
     public void onCreateContextMenu(ContextMenu menu, View v,
             ContextMenuInfo menuInfo) {
         super.onCreateContextMenu(menu, v, menuInfo);
         ExpandableListView.ExpandableListContextMenuInfo info=(ExpandableListView.ExpandableListContextMenuInfo)menuInfo;


     }
 }

4.运行实例：

二、动态添加和删除

结合List的add()和remove()方法实现动态添加和删除操作。

1.定义适配器类：

 package org.yayun.demo;

 import java.util.List;

 import android.app.Activity;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AbsListView;
 import android.widget.BaseExpandableListAdapter;
 import android.widget.TextView;

 //为expandable list view 提供内容的基类
 public class InfoDetailsAdapter extends BaseExpandableListAdapter {
     Activity activity;

     List<String> group;
     List<List<String>> child;

     public InfoDetailsAdapter(Activity a, List<String> group,
             List<List<String>> child) {
         activity = a;
         this.group = group;
         this.child = child;
     }

     // child method stub

     public Object getChild(int groupPosition, int childPosition) {
         // TODO Auto-generated method stub
         // System.out.println("*******************"+child.get(groupPosition).get(childPosition));
         return child.get(groupPosition).get(childPosition);
     }

     public long getChildId(int groupPosition, int childPosition) {
         // TODO Auto-generated method stub
         return childPosition;
     }

     public int getChildrenCount(int groupPosition) {
         // TODO Auto-generated method stub
         return child.get(groupPosition).size();
     }

     public View getChildView(int groupPosition, int childPosition,
             boolean isLastChild, View convertView, ViewGroup parent) {
         // TODO Auto-generated method stub
         String string = child.get(groupPosition).get(childPosition);
         return getGenericView(string);
     }

     // group method stub
     public Object getGroup(int groupPosition) {
         // TODO Auto-generated method stub
         return group.get(groupPosition);
     }

     public long getGroupId(int groupPosition) {
         // TODO Auto-generated method stub
         return groupPosition;
     }

     public int getGroupCount() {
         // TODO Auto-generated method stub
         return group.size();
     }

     public View getGroupView(int groupPosition, boolean isExpanded,
             View convertView, ViewGroup parent) {
         // TODO Auto-generated method stub
         String string = group.get(groupPosition);
         return getGenericView(string);
     }

     // View stub to create Group/Children 's View
     public TextView getGenericView(String s) {
         // Layout parameters for the ExpandableListView
         AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                 ViewGroup.LayoutParams.FILL_PARENT, 64);

         TextView text = new TextView(activity);
         text.setLayoutParams(lp);
         // Center the text vertically
         text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
         // Set the text starting position
         text.setPadding(36, 0, 0, 0);

         text.setText(s);
         return text;
     }

     public boolean hasStableIds() {
         // TODO Auto-generated method stub
         return false;
     }

     public boolean isChildSelectable(int groupPosition, int childPosition) {
         // TODO Auto-generated method stub
         return true;
     }

 }

2.main.xml:

 <p>xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="<a target=_blank href="http://schemas.android.com/apk/res/android">http://schemas.android.com/apk/res/androida>"
     android:id="@+id/layout"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:orientation="vertical" >p><p>    <ExpandableListView
         android:id="@+id/expandList"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content" />p><p>LinearLayout>p>

3.add.xml

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

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="姓名:" />

         <EditText
             android:id="@+id/add_name"
             android:layout_width="200dip"
             android:layout_height="wrap_content" />
     LinearLayout>

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="电话:" />

         <EditText
             android:id="@+id/add_phone"
             android:layout_width="200dip"
             android:layout_height="wrap_content" />
     LinearLayout>

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="性别:" />

         <EditText
             android:id="@+id/add_sex"
             android:layout_width="200dip"
             android:layout_height="wrap_content" />
     LinearLayout>

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="住址:" />

         <EditText
             android:id="@+id/add_home"
             android:layout_width="200dip"
             android:layout_height="wrap_content" />
     LinearLayout>

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <Button
             android:id="@+id/add_ok"
             android:layout_width="90dip"
             android:layout_height="wrap_content"
             android:text="OK" />

         <Button
             android:id="@+id/add_no"
             android:layout_width="90dip"
             android:layout_height="wrap_content"
             android:text="NO" />
     LinearLayout>

 LinearLayout>

4.delete.xml:

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

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="ID:" />

         <EditText
             android:id="@+id/delete_id"
             android:layout_width="200dip"
             android:layout_height="wrap_content" />
     LinearLayout>

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <Button
             android:id="@+id/delete_ok"
             android:layout_width="90dip"
             android:layout_height="wrap_content"
             android:text="OK" />

         <Button
             android:id="@+id/delete_no"
             android:layout_width="90dip"
             android:layout_height="wrap_content"
             android:text="NO" />
     LinearLayout>

 LinearLayout>

5.MainActivity.java:

 package org.yayun.demo;

 import java.util.ArrayList;
 import java.util.List;
 import android.app.Activity;
 import android.app.Dialog;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.ExpandableListView;
 import android.widget.Toast;
 import android.widget.ExpandableListView.OnChildClickListener;
 import android.widget.ExpandableListView.OnGroupClickListener;

 public class MainActivity extends Activity {

     public final static int MENU_ADD = Menu.FIRST;
     public final static int MENU_DELETE = Menu.FIRST + 1;

     ExpandableListView expandList;
     InfoDetailsAdapter adapter;

     Activity activity;

     List group;
     List> child;

     // 初始化group child内容
     public void initialData() {
         group = new ArrayList();
         child = new ArrayList>();

         addInfo("肥肥", new String[] { "234", "two 1", "three 1" });
         addInfo("肥蛋", new String[] { "one 2", "two 2", "three 2" });
         addInfo("垃圾肥", new String[] { "one 3", "two 3", "three 3" });
     }

     public void addInfo(String p, String[] c) {
         group.add(p);
         List item = new ArrayList();
         for (int i = 0; i < c.length; i++) {
             item.add(c[i]);
         }
         child.add(item);
     }

     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);

         activity = this;

         expandList = (ExpandableListView) findViewById(R.id.expandList);

         // 初始化各级元素
         initialData();

         // 适配器内容
         adapter = new InfoDetailsAdapter(this, group, child);

         expandList.setAdapter(adapter);

         expandList.setOnGroupClickListener(new OnGroupClickListener() {
             public boolean onGroupClick(ExpandableListView arg0, View arg1,
                     int arg2, long arg3) {
                 // TODO Auto-generated method stub
                 System.out.println("The row id of the group clicked" + arg3);
                 Toast.makeText(activity, "[Group Click]:" + arg2,
                         Toast.LENGTH_SHORT).show();
                 return false;
             }

         });
         expandList.setOnChildClickListener(new OnChildClickListener() {
             public boolean onChildClick(ExpandableListView arg0, View arg1,
                     int arg2, int arg3, long arg4) {
                 // TODO Auto-generated method stub
                 Toast.makeText(activity, "[Child Click]:" + arg2 + ":" + arg3,
                         Toast.LENGTH_SHORT).show();
                 return false;
             }
         });
     }

     // 下述2个函数处理Menu按钮的事件
     public boolean onCreateOptionsMenu(Menu menu) {
         // TODO Auto-generated method stub
         menu.add(0, MENU_ADD, 0, "     添加        ");
         menu.add(0, MENU_DELETE, 0, "     删除        ");

         return super.onCreateOptionsMenu(menu);
     }

     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
         case MENU_ADD:
             Log.i("", "FRIEND_ID");
             createDialogAdd();
             dialogAdd.show();
             break;
         case MENU_DELETE:
             Log.i("", "FRIEND_ID");
             createDialogDelete();
             dialogDelete.show();
             break;
         }
         return super.onOptionsItemSelected(item);
     }

     EditText add_name, add_phone, add_sex, add_home;
     EditText delete_id;

     Button add_ok, add_no;
     Button delete_ok, delete_no;

     Dialog dialogAdd, dialogDelete;

     public void createDialogAdd() {//创建对话框
         Log.i("", "createDialogAdd");
         View viewAdd = this.getLayoutInflater().inflate(R.layout.add, null);

         dialogAdd = new Dialog(this);
         dialogAdd.setContentView(viewAdd);
         dialogAdd.setTitle("输入新成员信息");

         add_name = (EditText) viewAdd.findViewById(R.id.add_name);
         add_phone = (EditText) viewAdd.findViewById(R.id.add_phone);
         add_sex = (EditText) viewAdd.findViewById(R.id.add_sex);
         add_home = (EditText) viewAdd.findViewById(R.id.add_home);

         add_ok = (Button) viewAdd.findViewById(R.id.add_ok);
         add_no = (Button) viewAdd.findViewById(R.id.add_no);

         add_ok.setOnClickListener(new OnClickListener() {//点击确定
             public void onClick(View v) {
                 // TODO Auto-generated method stub
                 String[] data = { add_phone.getText().toString(),
                         add_sex.getText().toString(),
                         add_home.getText().toString() };

                 addInfo(add_name.getText().toString(), data);

                 dialogAdd.dismiss();

                 adapter.notifyDataSetChanged();
             }
         });

         add_no.setOnClickListener(new OnClickListener() {//取消
             public void onClick(View v) {
                 // TODO Auto-generated method stub
                 dialogAdd.dismiss();
             }
         });
     }

     public void createDialogDelete() {//创建删除按钮
         View viewDelete = this.getLayoutInflater().inflate(R.layout.delete,
                 null);

         dialogDelete = new Dialog(this);
         dialogDelete.setContentView(viewDelete);
         dialogDelete.setTitle("删除指定成员");

         delete_id = (EditText) viewDelete.findViewById(R.id.delete_id);
         delete_ok = (Button) viewDelete.findViewById(R.id.delete_ok);
         delete_no = (Button) viewDelete.findViewById(R.id.delete_no);

         delete_ok.setOnClickListener(new OnClickListener() {
             public void onClick(View v) {
                 // TODO Auto-generated method stub

                 String id = delete_id.getText().toString();

                 if (!id.equals("")) {
                     int i = Integer.parseInt(id);
                     group.remove(i);
                     child.remove(i);

                     dialogDelete.dismiss();

                     adapter.notifyDataSetChanged();
                 }

             }
         });

         delete_no.setOnClickListener(new OnClickListener() {
             public void onClick(View v) {
                 // TODO Auto-generated method stub
                 dialogDelete.dismiss();
             }
         });
     }

 }

运行实例如下：

总结

expandableListView.setOnChildClickListener(new OnChildClickListenerImpl());//子项单击事件

expandableListView.setOnGroupClickListener(new OnGroupClickListenerImpl());//组项单击事件

expandableListView.setOnGroupCollapseListener(new OnGroupCollapseListenerImpl());//关闭分组事件

expandableListView.setOnGroupExpandListener(new OnGroupExpandListenerImpl());//展开分组事件

四个特有的事件监听。