树型组件：ExpandableListView

ListView组件可以为用户提供列表的显示功能，但是如果要想对这些列表数据进行分组的管理，则就需要使用android.widget.ExpandableListView组件完成

package org.lxh.demo;
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;
// 继承BaseExpandableListAdapter并覆写类中的抽象方法
public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    public String[] groups = { "我的好友", "家人", "同事", "黑名单" };// 组名称
    public String[][] children = {
            { "李兴华", "董鸣楠", "王月清", "周艳军" },
            { "父亲", "母亲" }, { "刘宏伟", "李祺", "刘媛" },
            { "票贩子", "造假商" } };        // 定义组项
    private Context context = null;        // 保存上下文对象
    public MyExpandableListAdapter(Context context) {    // 构造方法接收
        this.context = context;
    }
    @Override
    public Object getChild(int groupPosition, int childPosition) {    // 取得指定的子项
        return this.children[groupPosition][childPosition];
    }
    @Override
    public long getChildId(int groupPosition, int childPosition) {    // 取得子项ID
        return childPosition;
    }
    public TextView buildTextView() {    // 自定义方法，建立文本
        AbsListView.LayoutParams param = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT, 35);// 指定布局参数
        TextView textView = new TextView(this.context);// 创建TextView
        textView.setLayoutParams(param);    // 设置布局参数
        textView.setTextSize(15.0f);        // 设置文字大小
        textView.setGravity(Gravity.LEFT);        // 左对齐
        textView.setPadding(40, 8, 3, 3);    // 间距
        return textView;// 返回组件
    }
    @Override
    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {// 返回子项组件
        TextView textView = buildTextView();    // 创建TextView
        textView.setText(getChild(groupPosition,
                childPosition).toString());        // 设置显示文字
        return textView;
    }
    @Override
    public int getChildrenCount(int groupPosition) {    // 取得子项个数
        return this.children[groupPosition].length;    // 取得子项个数
    }
    @Override
    public Object getGroup(int groupPosition) {// 取得组对象
        return this.groups[groupPosition];
    }
    @Override
    public int getGroupCount() {    // 取得组个数
        return this.groups.length;
    }
    @Override
    public long getGroupId(int groupPosition) {// 取得组ID
        return groupPosition;
    }
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {    // 取得组显示组件
        TextView textView = buildTextView();    // 建立组件
        textView.setText(this.getGroup(groupPosition).toString());    // 设置文字
        return textView;
    }
    @Override
    public boolean hasStableIds() {
        return true;
    }
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

020719树型组件：ExpandableListView.ppt