android 可展開（收縮）的列表ListView(ExpandableListView)

每天都在用QQ聊天，今天突然一想，android怎么實現列表的分組展開呢？看了看api，發現其實現過程也很簡單。先看一下最終效果吧！

 

1、首先創建我們的Activity，繼承 android.app.ExpandableListActivity，直接看代碼吧。

package com.ideasandroid.sample;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import com.ideasandroid.sample.adapter.IdeasExpandableListAdapter;
 
/**
 * @author IdeasAndroid
 * 可展開（收縮）列表示例
 */
public class IdeasExpandableListView extends ExpandableListActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //設置列表適配器IdeasExpandableListAdapter
        setListAdapter(new IdeasExpandableListAdapter(this));
    }
}

2、創建適配器，繼承android.widget.BaseExpandableListAdapter。

package com.ideasandroid.sample.adapter;
 
import java.util.ArrayList;
import java.util.List;
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;
 
/**
 * @author IdeasAndroid 
 * 可展開（收縮）列表示例
 */
public class IdeasExpandableListAdapter extends BaseExpandableListAdapter {
 
        private Context mContext = null;
        // 測試數據，開發時可能來自數據庫，網絡....
        private String[] groups = { "家人", "朋友", "同事" };
        private String[] familis = { "老爸", "老媽", "妹妹" };
        private String[] friends = { "小李", "張三", "李四" };
        private String[] colleagues = { "陳總", "李工", "李客戶" };
 
        private List<String> groupList = null;
        private List<List<String>> itemList = null;
 
        public IdeasExpandableListAdapter(Context context) {
                this.mContext = context;
                groupList = new ArrayList<String>();
                itemList = new ArrayList<List<String>>();
                initData();
        }
 
        /**
         * 初始化數據，將相關數據放到List中，方便處理
         */
        private void initData() {
                for (int i = 0; i < groups.length; i++) {
                        groupList.add(groups[i]);
                }
                List<String> item1 = new ArrayList<String>();
                for (int i = 0; i < familis.length; i++) {
                        item1.add(familis[i]);
                }
 
                List<String> item2 = new ArrayList<String>();
                for (int i = 0; i < friends.length; i++) {
                        item2.add(friends[i]);
                }
 
                List<String> item3 = new ArrayList<String>();
                for (int i = 0; i < colleagues.length; i++) {
                        item3.add(colleagues[i]);
                }
 
                itemList.add(item1);
                itemList.add(item2);
                itemList.add(item3);
        }
 
        public boolean areAllItemsEnabled() {
                return false;
        }
 
        /*
         * 設置子節點對象，在事件處理時返回的對象，可存放一些數據
         */
        public Object getChild(int groupPosition, int childPosition) {
                return itemList.get(groupPosition).get(childPosition);
        }
 
        public long getChildId(int groupPosition, int childPosition) {
                return childPosition;
        }
 
        /*
         * 字節點視圖，這里我們顯示一個文本對象
         */
        public View getChildView(int groupPosition, int childPosition,
                        boolean isLastChild, View convertView, ViewGroup parent) {
                TextView text = null;
                if (convertView == null) {
                        text = new TextView(mContext);
                } else {
                        text = (TextView) convertView;
                }
                // 獲取子節點要顯示的名稱
                String name = (String) itemList.get(groupPosition).get(childPosition);
                // 設置文本視圖的相關屬性
                AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                                ViewGroup.LayoutParams.FILL_PARENT, 40);
                text.setLayoutParams(lp);
                text.setTextSize(18);
                text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
                text.setPadding(45, 0, 0, 0);
                text.setText(name);
                return text;
        }
 
        /*
         * 返回當前分組的字節點個數
         */
        public int getChildrenCount(int groupPosition) {
                return itemList.get(groupPosition).size();
        }
 
        /*
         * 返回分組對象，用於一些數據傳遞，在事件處理時可直接取得和分組相關的數據
         */
        public Object getGroup(int groupPosition) {
                return groupList.get(groupPosition);
        }
 
        /*
         * 分組的個數
         */
        public int getGroupCount() {
                return groupList.size();
        }
 
        public long getGroupId(int groupPosition) {
                return groupPosition;
        }
 
        /*
         * 分組視圖，這里也是一個文本視圖
         */
        public View getGroupView(int groupPosition, boolean isExpanded,
                        View convertView, ViewGroup parent) {
                TextView text = null;
                if (convertView == null) {
                        text = new TextView(mContext);
                } else {
                        text = (TextView) convertView;
                }
                String name = (String) groupList.get(groupPosition);
                AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                                ViewGroup.LayoutParams.FILL_PARENT, 40);
                text.setLayoutParams(lp);
                text.setTextSize(18);
                text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
                text.setPadding(36, 0, 0, 0);
                text.setText(name);
                return text;
        }
 
        /*
         * 判斷分組是否為空，本示例中數據是固定的，所以不會為空，我們返回false 
         * 如果數據來自數據庫，網絡時，可以把判斷邏輯寫到這個方法中，如果為空
         * 時返回true
         */
        public boolean isEmpty() {
                return false;
        }
 
        /*
         * 收縮列表時要處理的東西都放這兒
         */
        public void onGroupCollapsed(int groupPosition) {
 
        }
 
        /*
         * 展開列表時要處理的東西都放這兒
         */
        public void onGroupExpanded(int groupPosition) {
 
        }
 
        /*
         * Indicates whether the child and group IDs are stable across changes to
         * the underlying data.
         */
        public boolean hasStableIds() {
                return false;
        }
 
        /*
         * Whether the child at the specified position is selectable.
         */
        public boolean isChildSelectable(int groupPosition, int childPosition) {
                return true;
        }
}

IdeasExpandableListView.rar

轉：http://www.apkbus.com/android-54271-1-1.html