Adroid 展开收起效果实现

Layout

<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:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    android:paddingBottom="@dimen/activity_vertical_margin"

    tools:context=".ExpandableListViewActivity">



    <ExpandableListView

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:id="@+id/ecpandable"

        />

</RelativeLayout>

JAVA代码



package com.example.wequst.test2;



import android.app.Activity;

import android.app.AlertDialog;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AbsListView;

import android.widget.BaseExpandableListAdapter;

import android.widget.ExpandableListAdapter;

import android.widget.ExpandableListView;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.TextView;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;



public class ExpandableListViewActivity extends Activity {



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_expandable_list_view);

        /**BaseExpandableListAdapter实现了ExpandableListAdapter*/

        final ExpandableListAdapter adapter = new BaseExpandableListAdapter(){



            /**----------定义数组-------------------------------------------------------------------*/

            private int[] images = new int[]{

                    R.drawable.ic_launcher,

                    R.drawable.ic_launcher,

                    R.drawable.ic_launcher

            };

            private String[] armTypes = new String[]{

                    "神族","虫族","人族"

            };

            private String[][] arms = new String[][]{

                    {"狂战士","龙骑士","黑暗圣堂"},

                    {"小狗","飞龙","自爆妃子"},

                    {"步兵","伞兵","护士mm"}

            };



/*===========组元素表示可折叠的列表项，子元素表示列表项展开后看到的多个子元素项=============*/



            /**----------得到armTypes和arms中每一个元素的ID-------------------------------------------*/



            //获取组在给定的位置编号，即armTypes中元素的ID

            @Override

            public long getGroupId(int groupPosition) {

                return groupPosition;

            }



            //获取在给定的组的儿童的ID，就是arms中元素的ID

            @Override

            public long getChildId(int groupPosition, int childPosition) {

                return childPosition;

            }



            /**----------根据上面得到的ID的值，来得到armTypes和arms中元素的个数 ------------------------*/



            //获取的群体数量，得到armTypes里元素的个数

            @Override

            public int getGroupCount() {

                return armTypes.length;

            }



            //取得指定组中的儿童人数，就是armTypes中每一个种族它军种的个数

            @Override

            public int getChildrenCount(int groupPosition) {

                return arms[groupPosition].length;

            }



            /**----------利用上面getGroupId得到ID，从而根据ID得到armTypes中的数据，并填到TextView中 -----*/



            //获取与给定的组相关的数据，得到数组armTypes中元素的数据

            @Override

            public Object getGroup(int groupPosition) {

                return armTypes[groupPosition];

            }



            //获取一个视图显示给定组，存放armTypes

            @Override

            public View getGroupView(int groupPosition, boolean isExpanded,

                                     View convertView, ViewGroup parent) {

                TextView textView = getTextView();//调用定义的getTextView()方法

                textView.setText(getGroup(groupPosition).toString());//添加数据

                return textView;

            }



            /**----------利用上面getChildId得到ID，从而根据ID得到arms中的数据，并填到TextView中---------*/



            //获取与孩子在给定的组相关的数据,得到数组arms中元素的数据

            @Override

            public Object getChild(int groupPosition, int childPosition) {

                return arms[groupPosition][childPosition];

            }



            //获取一个视图显示在给定的组 的儿童的数据，就是存放arms

            @Override

            public View getChildView(int groupPosition, int childPosition, boolean isLastChild,

                                     View convertView, ViewGroup parent) {

                LinearLayout ll = new LinearLayout(ExpandableListViewActivity.this);

                ImageView logo = new ImageView(ExpandableListViewActivity.this);

                logo.setImageResource(images[groupPosition]);//添加图片

                ll.addView(logo);

                TextView textView = getTextView();//调用定义的getTextView()方法

                textView.setText(getChild(groupPosition,childPosition).toString());//添加数据

                ll.addView(textView);

                return ll;

            }



            /**------------------自定义一个设定TextView属性的方法----------------------------------------------*/



            //定义一个TextView

            private TextView getTextView(){

                AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,100);

                TextView textView = new TextView(ExpandableListViewActivity.this);

                textView.setLayoutParams(lp);

                textView.setPadding(70, 0, 0, 0);

                textView.setTextSize(20);

                return textView;

            }



            /**-------------------其他设置-------------------------------------------------------------------*/



            //孩子在指定的位置是可选的，即：arms中的元素是可点击的

            @Override

            public boolean isChildSelectable(int groupPosition,

                                             int childPosition) {

                return true;

            }



            //表示孩子是否和组ID是跨基础数据的更改稳定

            public boolean hasStableIds() {

                return true;

            }

        };



        /**使用适配器*/

        final ExpandableListView expandListView = (ExpandableListView) this.findViewById(R.id.ecpandable);

        expandListView.setAdapter(adapter);



        expandListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {

            @Override

            public boolean onChildClick(ExpandableListView parent, View v,

                                        int groupPosition, int childPosition, long id) {

                return true;

            }

        });



        expandListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {

            @Override

            public boolean onGroupClick(ExpandableListView parent, View v,

                                        int groupPosition, long id) {



                int i=adapter.getChildrenCount(groupPosition);

                if(i==0)

                {



                }

                return false;   //默认为false，设为true时，点击事件不会展开Group

            }

        });

    }



}