ExpandableListView小结

Java代码： package com.example.expandablelistviewdemo;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import android.os.Bundle;import android.app.Activity;import android.content.Context;import android.view.Menu;import android.view.View;import android.widget.CheckedTextView;import android.widget.ExpandableListView;import android.widget.TextView;import android.widget.ExpandableListView.OnChildClickListener;/** * Example application with ExpandableListView and CheckedTextView as list item. * Texts of selected list items are displayed in parent view. *  * @author Lauri Nevala *  * */public class MainActivity extends Activity {private SettingsListAdapter adapter;private ExpandableListView categoriesList;private ArrayList<Category> categories;protected Context mContext;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mContext = this;categoriesList = (ExpandableListView)findViewById(R.id.categories);categories = Category.getCategories();adapter = new SettingsListAdapter(this, categories, categoriesList);        categoriesList.setAdapter(adapter);        categoriesList.expandGroup(0);                categoriesList.setOnChildClickListener(new OnChildClickListener() {@Overridepublic boolean onChildClick(ExpandableListView parent, View v,int groupPosition, int childPosition, long id) {CheckedTextView checkbox = (CheckedTextView)v.findViewById(R.id.list_item_text_child);checkbox.toggle();// find parent view by tagView parentView = categoriesList.findViewWithTag(categories.get(groupPosition).name);if(parentView != null) {TextView sub = (TextView)parentView.findViewById(R.id.list_item_text_subscriptions);if(sub != null) {Category category = categories.get(groupPosition);if(checkbox.isChecked()) {// add child category to parent's selection listcategory.selection.add(checkbox.getText().toString());// sort list in alphabetical orderCollections.sort(category.selection, new CustomComparator());}else {// remove child category from parent's selection listcategory.selection.remove(checkbox.getText().toString());}// display selection listsub.setText(category.selection.toString());}}return true;}});}public class CustomComparator implements Comparator<String> {        @Override        public int compare(String o1, String o2) {            return o1.compareTo(o2);                    }    }    @Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}activity_main.xml布局代码：<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"    android:background="@drawable/food"    tools:context=".MainActivity" ><ExpandableListView   android:id="@+id/categories"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:layout_alignParentTop="true"   android:layout_alignParentLeft="true">   categoriesList.expandGroup(0);</ExpandableListView></RelativeLayout>setting_list_item_child.xml代码：<?xml version="1.0" encoding="utf-8"?> <LinearLayout        xmlns:android="http://schemas.android.com/apk/res/android"        android:orientation="horizontal"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:id="@+id/list_item_child"        android:gravity="center_vertical">     <CheckedTextView        android:id="@+id/list_item_text_child"        android:layout_width="0dip"        android:layout_height="wrap_content"        android:layout_gravity="center_vertical"        android:drawableLeft="?android:attr/listChoiceIndicatorMultiple"        android:checked="false"        android:gravity="center_vertical"        android:padding="10dp"android:layout_weight="1"android:layout_marginLeft="35dp" /></LinearLayout>  settings_list_item_parent.xml代码：<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="horizontal"android:layout_width="fill_parent"android:layout_height="fill_parent"android:id="@+id/list_item"><RelativeLayout     android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_gravity="center_vertical"    > <TextViewandroid:layout_width="fill_parent"android:layout_height="wrap_content"android:id="@+id/list_item_text_view"style="?android:attr/preferenceStyle"android:textSize="15sp"android:paddingBottom="3dp"android:paddingTop="15dp"android:layout_marginLeft="45dp" /><TextView   android:id="@+id/list_item_text_subscriptions"   style="?android:attr/preferenceStyle"   android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:layout_below="@id/list_item_text_view"   android:layout_marginLeft="45dp"       android:textColor="#696969"   android:textSize="12sp"   android:paddingBottom="3dp"    /></RelativeLayout> </LinearLayout>  

         显示好友QQ那样的列表，可以展开，可以收起，在android中，以往用的比较多的是listview，虽然可以实现列表的展示，但在某些情况下，我们还是希望用到可以分组并实现收缩的列表，那就要用到android的ExpandableListView，天研究了一下这个的用法，也参考了很多资料动手写了一个小demo，实现了基本的功能，但界面优化方面做得还不够好，有待改进。下面直接上效果图以及源代码如上~！