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先看效果:
代码:
MainActivity:
package com.example.administrator.expland; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseExpandableListAdapter; import android.widget.ExpandableListView; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private ExpandableListView expandListview; private String[] groups = {"A", "B", "C", "D", "E"}; //注意,字符数组不要写成{{"A1,A2,A3,A4"}, {"B1,B2,B3,B4,B5"}, {"C1,C2,C3,C4"}}*/ private String[][] childs = {{"A1", "A2", "A3", "A4"}, {"A1", "A2", "A3", "B4"}, {"A1", "A2", "A3", "C4"}, {"A1", "A2", "A3", "C4"}, {"A1", "A2", "A3", "C4"}}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); expandListview = (ExpandableListView) findViewById(R.id.expandListview); expandListview.setAdapter(new MyExpandableListView()); } //为ExpandableListView自定义适配器 class MyExpandableListView extends BaseExpandableListAdapter { //返回一级列表的个数 @Override public int getGroupCount() { return groups.length; } //返回每个二级列表的个数 @Override public int getChildrenCount(int groupPosition) { //参数groupPosition表示第几个一级列表 return childs[groupPosition].length; } //返回一级列表的单个item(返回的是对象) @Override public Object getGroup(int groupPosition) { return groups[groupPosition]; } @Override public Object getChild(int groupPosition, int childPosition) { return childs[groupPosition][childPosition]; } @Override public long getGroupId(int groupPosition) { return groupPosition; } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } @Override public boolean hasStableIds() { return true; } @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { GroupViewHolder groupViewHolder; if (convertView == null) { convertView = LayoutInflater.from(MainActivity.this).inflate(R.layout.item_group, parent, false); groupViewHolder = new GroupViewHolder(); groupViewHolder.tvTitle = (TextView) convertView.findViewById(R.id.tv_group); convertView.setTag(groupViewHolder); } else { groupViewHolder = (GroupViewHolder) convertView.getTag(); } groupViewHolder.tvTitle.setText(groups[groupPosition]); return convertView; } @Override public View getChildView(int groupPosition, int childPosition, boolean b, View convertView, ViewGroup parent) { ChildViewHolder childViewHolder; if (convertView == null) { convertView = LayoutInflater.from(MainActivity.this).inflate(R.layout.item_child, parent, false); childViewHolder = new ChildViewHolder(); childViewHolder.tvTitle = (TextView) convertView.findViewById(R.id.tv_child); convertView.setTag(childViewHolder); } else { childViewHolder = (ChildViewHolder) convertView.getTag(); } childViewHolder.tvTitle.setText(childs[groupPosition][childPosition]); return convertView; } @Override public boolean isChildSelectable(int i, int i1) { return true; } } static class GroupViewHolder { TextView tvTitle; } static class ChildViewHolder { TextView tvTitle; } }布局:
1.activity_main:
<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.administrator.expland.MainActivity"> <ExpandableListView android:id="@+id/expandListview" android:layout_width="690px" android:layout_height="544px"></ExpandableListView> </android.support.constraint.ConstraintLayout>2.item_group:
<?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"> <TextView android:id="@+id/tv_group" android:layout_width="wrap_content" android:layout_height="30dp" android:gravity="center" android:text="group text" android:layout_marginLeft="50dp" /> </LinearLayout>3.item_child:
<?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"> <ImageView android:id="@+id/iv_child" android:layout_width="30dp" android:layout_height="30dp" android:layout_marginLeft="50dp" android:src="@mipmap/ic_launcher" /> <TextView android:id="@+id/tv_child" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="item text" /> </LinearLayout>