[Android]BaseExpandableListAdapter實現可摺疊的列表

標籤：android   expandablelistview   

使用BaseExpandableListAdapter 可以實現所謂的可摺疊的列表，例如QQ裡好友的分組的功能。

基於基於BaseExpandableListAdapter擴充的ExpandableList用法，現在網上流行的主要有兩種：第一種是向BaseExpandableListAdapter傳入兩個數組，第一個是表示Group（目錄頭）資訊的一維數組，第二個是表示Child（目錄子項）的二維數組數組；第二種是構建兩個類，一個是表示目錄資訊的GroupInfo類，另一個是表示子項資訊的ChildInfo類，然後傳入BaseExpandableListAdapter。通過對比發現，第一種方法由於數組是固定的，而實際項目中往往需要動態變化的目錄和子項，因此用處不大，第二種方法檔案太多，實現複雜。這裡提供一種方法，傳遞兩個個動態二維數組來實現目錄結構。

package com.example.test;import java.util.ArrayList;import android.os.Bundle;import android.app.Activity;import android.graphics.Color;import android.graphics.drawable.ColorDrawable;import android.view.Gravity;import android.view.Menu;import android.view.View;import android.view.ViewGroup;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.view.View.OnClickListener;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        //Group資料        ArrayList<String> groupList = new ArrayList<String>();        groupList.add("我的好友");        groupList.add("我的親人");        groupList.add("我的同學");        //Child資料        ArrayList<String> itemList1 = new ArrayList<String>();        itemList1.add("小米");        itemList1.add("小李");        ArrayList<String> itemList2 = new ArrayList<String>();        itemList2.add("小麗");        itemList2.add("小小");        itemList2.add("小可");        ArrayList<String> itemList3 = new ArrayList<String>();        itemList3.add("小南");        itemList3.add("小飛");        itemList3.add("小丁");        itemList3.add("小美");        ArrayList<ArrayList<String>> childList = new ArrayList<ArrayList<String>>();        childList.add(itemList1);        childList.add(itemList2);        childList.add(itemList3);        //可摺疊List        ExpandableListView list = new ExpandableListView(this);        ExpandableListAdapter mAdapter = new MyExpandableListAdapter(groupList, childList);        list.setAdapter(mAdapter);        list.setCacheColorHint(0x00000000);        list.setSelector(new ColorDrawable(Color.TRANSPARENT));        list.setGroupIndicator(null);        for (int i = 0; i < mAdapter.getGroupCount(); i++) {            list.expandGroup(i);        }        setContentView(list);    }    //Adapter    private class MyExpandableListAdapter extends BaseExpandableListAdapter {        private ArrayList<String> groupList;        private ArrayList<ArrayList<String>> childList;        MyExpandableListAdapter(ArrayList<String> groupList, ArrayList<ArrayList<String>> childList) {            this.groupList = groupList;            this.childList = childList;        }        public Object getChild(int groupPosition, int childPosition) {            return childList.get(groupPosition).get(childPosition);        }        private int selectedGroupPosition = -1;        private int selectedChildPosition = -1;        public void setSelectedPosition(int selectedGroupPosition, int selectedChildPosition) {            this.selectedGroupPosition = selectedGroupPosition;            this.selectedChildPosition = selectedChildPosition;        }        public long getChildId(int groupPosition, int childPosition) {            return childPosition;        }        public int getChildrenCount(int groupPosition) {            return childList.get(groupPosition).size();        }        public View getChildView(final int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {            TextView textView = null;            if (convertView == null) {                textView = new TextView(MainActivity.this);                textView.setPadding(32, 10, 0, 10);                convertView = textView;            } else {                textView = (TextView) convertView;            }            textView.setText(getChild(groupPosition, childPosition).toString());            if (groupPosition == selectedGroupPosition) {                if (childPosition == selectedChildPosition) {                    textView.setBackgroundColor(0xffb6ddee);                } else {                    textView.setBackgroundColor(Color.TRANSPARENT);                }            }            textView.setOnClickListener(new OnClickListener() {                public void onClick(View v) {                    setSelectedPosition(groupPosition, childPosition);                    notifyDataSetChanged();                }            });            return textView;        }        public Object getGroup(int groupPosition) {            return groupList.get(groupPosition);        }        public int getGroupCount() {            return groupList.size();        }        public long getGroupId(int groupPosition) {            return groupPosition;        }        public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {            LinearLayout cotain = new LinearLayout(MainActivity.this);            cotain.setPadding(0, 10, 0, 10);            cotain.setGravity(Gravity.CENTER_VERTICAL);            ImageView imgIndicator = new ImageView(MainActivity.this);            TextView textView = new TextView(MainActivity.this);            textView.setText(getGroup(groupPosition).toString());            textView.setPadding(5, 0, 0, 0);            if (isExpanded) {                imgIndicator.setBackgroundResource(R.drawable.bg_arrow_up);            } else {                imgIndicator.setBackgroundResource(R.drawable.bg_arrow_down);            }            cotain.addView(imgIndicator);            cotain.addView(textView);            return cotain;        }        public boolean hasStableIds() {            return true;        }        public boolean isChildSelectable(int groupPosition, int childPosition) {            return true;        }    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.main, menu);        return true;    }}

groupList 用於組名（類似QQ的好友、同學、朋友），

childList 每個元素都是一組子資料（類似QQ同學中的張三，李四的集合)

[Android]BaseExpandableListAdapter實現可摺疊的列表