可扩展的列表组件

ExpandableListView(可扩展列表组件).ExpandableListView所显示的列表项应该有由ExpandableListAdapter提供。
实现ExpandableListAdapter的三种常见方式：

扩展BaseExpandableListAdapter 实现ExpandableListAdapter。
使用SimpleExpandableListAdapter将两个List集合包装成ExpandableListAdapter。
使用SimpleCursorTreeAdapter将Cursor中的数据包装成SimpleCursorTreeAdapter。
布局如下：

布局简单，后面的LinearLayout，TextView和ImageView是直接在代码中获取的
<?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: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="com.example.expandablelistview.MainActivity"><ExpandableListView
       android:layout_width="match_parent"android:layout_height="match_parent"android:childDivider="@color/colorAccent"android:id="@+id/elistview"android:dividerHeight="2dp"></ExpandableListView></LinearLayout>
childDivider是指定各子列表项之间的分隔条

这里写图片描述

package com.example.expandablelistview;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.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;public class MyExpandableListView extends BaseExpandableListAdapter {
//这里的Context是为了给MainActivity传数据的private Context context;public MyExpandableListView(Context context) {this.context = context;}int[] image = new int[]{R.mipmap.kemic , R.mipmap.d, R.mipmap.abc};String[] armTypes = new String[]{"科比", "霍祁君", "全智贤"};String[][] arms = new String[][]{{"凌晨四点的洛杉矶", "你的后仰没有酒", "我却醉的像条狗", "我的青春"},{"羊驼王子", "霍霍", "需要人陪", "一首简单的歌"},{"人生大赢家","气质女神","柔和","灵气"}};//获取指定组位置，指定子列表项处的子列表项数据@Overridepublic Object getChild(int groupPosition, int childPosition) {return arms[groupPosition][childPosition];}@Overridepublic long getChildId(int groupPosition, int childPosition) {return childPosition;}@Overridepublic int getChildrenCount(int groupPosition) {return arms[groupPosition].length;}private TextView getTextView(){AbsListView.LayoutParams layoutParams = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,64);//注意这里context和this的区别TextView textView = new TextView(context);textView.setLayoutParams(layoutParams);textView.setGravity(Gravity.CENTER_VERTICAL|Gravity.LEFT);textView.setPadding(36,0,0,0);textView.setTextSize(20);return  textView;}//该方法决定每个子选项的外观@Overridepublic View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {TextView textView=getTextView();textView.setText(getChild(groupPosition,childPosition).toString());return textView;}//获取指定组位置处的选项@Overridepublic Object getGroup(int groupPosition) {return armTypes[groupPosition];}@Overridepublic int getGroupCount() {return armTypes.length;}@Overridepublic long getGroupId(int groupPosition) {return groupPosition;}//该方法决定每个组选项的外观@Overridepublic View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {LinearLayout linearLayout=new LinearLayout(context);linearLayout.setOrientation(LinearLayout.HORIZONTAL);ImageView  images = new ImageView(context);images.setImageResource(image[groupPosition]);images.setMaxWidth(100);linearLayout.addView(images);TextView textView = getTextView();textView.setText(getGroup(groupPosition).toString());linearLayout.addView(textView);return linearLayout;}@Overridepublic boolean isChildSelectable(int groupPosition, int childPosition) {return true;}@Overridepublic boolean hasStableIds() {return true;}
}

package com.example.expandablelistview;import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;public class MainActivity extends AppCompatActivity {private ExpandableListView expandableListView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);expandableListView= (ExpandableListView) findViewById(R.id.elistview);MyExpandableListView expandableListViewAdapter=new MyExpandableListView(this);expandableListView.setAdapter(expandableListViewAdapter);}
}