22.Android之ExpandableListView树形列表学习

Android经常用到树形菜单，一般ExpandableListView可以满足这个需要，今天学习下。

XML代码：

<?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"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <Button
            android:id="@+id/btn_tree"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="两层结构" />

     
        <Button
            android:id="@+id/btn_supertree"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="三层结构" />

    </LinearLayout>

    <ExpandableListView
        android:id="@+id/expandlist1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </ExpandableListView>

</LinearLayout>

接下来增加两个类TreeViewAdapter，SuperTreeViewAdaper继承BaseExpandableListAdapter，实现两层结构和三层结构效果：

TreeViewAdapter代码：

package com.example.expandlistdemo;

import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

public class TreeViewAdapter extends BaseExpandableListAdapter {

    public static final int ItemHeight = 48;
    public static final int PaddingLeft = 36;
    private int myPaddingLeft = 0;

    static public class TreeNode {
        Object parent;
        List childs = new ArrayList();
    }

    List<TreeNode> treeNodes = new ArrayList<TreeNode>();
    Context parentContext;

    public TreeViewAdapter(Context view, int myPaddingLeft) {
        parentContext = view;
        this.myPaddingLeft = myPaddingLeft;
    }

    public List<TreeNode> GetTreeNode() {
        return treeNodes;
    }

    public void UpdateTreeNode(List<TreeNode> nodes) {
        treeNodes = nodes;
    }

    public void RemoveAll() {
        treeNodes.clear();
    }

    public Object getChild(int groupPosition, int childPosition) {
        return treeNodes.get(groupPosition).childs.get(childPosition);
    }

    public int getChildrenCount(int groupPosition) {
        return treeNodes.get(groupPosition).childs.size();
    }

    static public TextView getTextView(Context context) {
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT, ItemHeight);

        TextView textView = new TextView(context);
        textView.setLayoutParams(lp);
        textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
        return textView;
    }

    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        TextView textView = getTextView(this.parentContext);
        textView.setText(getChild(groupPosition, childPosition).toString());
        textView.setPadding(myPaddingLeft + PaddingLeft, 0, 0, 0);
        return textView;
    }

    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        TextView textView = getTextView(this.parentContext);
        textView.setText(getGroup(groupPosition).toString());
        textView.setPadding(myPaddingLeft + (PaddingLeft >> 1), 0, 0, 0);
        return textView;
    }

    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    public Object getGroup(int groupPosition) {
        return treeNodes.get(groupPosition).parent;
    }

    public int getGroupCount() {
        return treeNodes.size();
    }

    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    public boolean hasStableIds() {
        return true;
    }

}

SuperTreeViewAdaper代码：

package com.example.expandlistdemo;

import java.util.ArrayList;
import java.util.List;
import com.example.expandlistdemo.TreeViewAdapter.TreeNode;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupCollapseListener;
import android.widget.ExpandableListView.OnGroupExpandListener;
import android.widget.TextView;

public class SuperTreeViewAdaper extends BaseExpandableListAdapter {

    static public class SuperTreeNode {
        Object parent;
        // 二级树形菜单的结构体
        List<TreeNode> childs = new ArrayList<TreeNode>();
    }

    private List<SuperTreeNode> superTreeNodes = new ArrayList<SuperTreeNode>();
    private Context parentContext;
    private OnChildClickListener stvClickEvent;// 外部回调函数

    public SuperTreeViewAdaper(Context view, OnChildClickListener stvClickEvent) {
        parentContext = view;
        this.stvClickEvent = stvClickEvent;
    }

    public List<SuperTreeNode> GetTreeNode() {
        return superTreeNodes;
    }

    public void UpdateTreeNode(List<SuperTreeNode> node) {
        superTreeNodes = node;
    }

    public void RemoveAll() {
        superTreeNodes.clear();
    }

    public Object getChild(int groupPosition, int childPosition) {
        return superTreeNodes.get(groupPosition).childs.get(childPosition);
    }

    public int getChildrenCount(int groupPosition) {
        return superTreeNodes.get(groupPosition).childs.size();
    }

    public ExpandableListView getExpandableListView() {
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT, TreeViewAdapter.ItemHeight);
        ExpandableListView superTreeView = new ExpandableListView(parentContext);
        superTreeView.setLayoutParams(lp);
        return superTreeView;
    }

    /**
     * 三层树结构中的第二层是一个ExpandableListView
     */
    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        // 是
        final ExpandableListView treeView = getExpandableListView();
        final TreeViewAdapter treeViewAdapter = new TreeViewAdapter(
                this.parentContext, 0);
        List<TreeNode> tmp = treeViewAdapter.GetTreeNode();// 临时变量取得TreeViewAdapter的TreeNode集合，可为空
        final TreeNode treeNode = (TreeNode) getChild(groupPosition,
                childPosition);
        tmp.add(treeNode);
        treeViewAdapter.UpdateTreeNode(tmp);
        treeView.setAdapter(treeViewAdapter);

        // 关键点：取得选中的二级树形菜单的父子节点,结果返回给外部回调函数
        treeView.setOnChildClickListener(this.stvClickEvent);

        /**
         * 关键点：第二级菜单展开时通过取得节点数来设置第三级菜单的大小
         */
        treeView.setOnGroupExpandListener(new OnGroupExpandListener() {
            @Override
            public void onGroupExpand(int groupPosition) {

                AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                        ViewGroup.LayoutParams.FILL_PARENT, (treeNode.childs
                                .size() + 1) * TreeViewAdapter.ItemHeight + 10);
                treeView.setLayoutParams(lp);
            }
        });

        /**
         * 第二级菜单回收时设置为标准Item大小
         */
        treeView.setOnGroupCollapseListener(new OnGroupCollapseListener() {
            @Override
            public void onGroupCollapse(int groupPosition) {

                AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
                        ViewGroup.LayoutParams.FILL_PARENT,
                        TreeViewAdapter.ItemHeight);
                treeView.setLayoutParams(lp);
            }
        });
        treeView.setPadding(TreeViewAdapter.PaddingLeft, 0, 0, 0);
        return treeView;
    }

    /**
     * 三级树结构中的首层是TextView,用于作为title
     */
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        TextView textView = TreeViewAdapter.getTextView(this.parentContext);
        textView.setText(getGroup(groupPosition).toString());
        textView.setPadding(TreeViewAdapter.PaddingLeft, 0, 0, 0);
        return textView;
    }

    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    public Object getGroup(int groupPosition) {
        return superTreeNodes.get(groupPosition).parent;
    }

    public int getGroupCount() {
        return superTreeNodes.size();
    }

    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    public boolean hasStableIds() {
        return true;
    }
}

修改下MainActivity.java：

package com.example.expandlistdemo;

import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.Toast;

public class MainActivity extends Activity {

    private Button btnTree;
    private Button btnSuperTree;
    private ExpandableListView expandlist;
    private TreeViewAdapter adapter;
    private SuperTreeViewAdaper superAdapter;

    public String[] groupTree = { "老师", "学生", "朋友" };
    public String[][] child = { { "王老师", "陈老师", "李老师", "黄老师" },
            { "学生甲", "学生乙", "学生丙" }, { "朋友甲", "朋友丁" } };

    public String[] parent = { "老师", "学生" };
    public String[][][] child_grandson = { { { "王老师" }, { "AA", "AAA" } },
            { { "陈老师" }, { "BBB", "BBBB", "BBBBB" } },
            { { "李老师" }, { "CCC", "CCCC" } },
            { { "黄老师" }, { "DDD", "DDDD", "DDDDD" } } };

    /**
     * 三级树形菜单的事件不再可用，本函数由三级树形菜单的子项（二级菜单）进行回调
     */
    OnChildClickListener stvClickEvent = new OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView parent, View v,
                int groupPosition, int childPosition, long id) {

            String str = "parent id:" + String.valueOf(groupPosition)
                    + ",children id:" + String.valueOf(childPosition);
            Toast.makeText(getApplicationContext(), str, 300).show();

            return false;

        }

    };
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnTree = (Button) findViewById(R.id.btn_tree);
        btnSuperTree = (Button) findViewById(R.id.btn_supertree);

        adapter = new TreeViewAdapter(this, TreeViewAdapter.PaddingLeft >> 1);

        superAdapter = new SuperTreeViewAdaper(this, stvClickEvent);
        expandlist = (ExpandableListView) findViewById(R.id.expandlist1);

        btnTree.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                adapter.RemoveAll();
                adapter.notifyDataSetChanged();
                superAdapter.RemoveAll();
                superAdapter.notifyDataSetChanged();
 
                List treeNode = adapter.GetTreeNode();
                for (int i = 0; i < groupTree.length; i++) {
                    TreeViewAdapter.TreeNode node = new TreeViewAdapter.TreeNode();
                    node.parent = groupTree[i];
                    for (int ii = 0; ii < child[i].length; ii++) {
                        node.childs.add(child[i][ii]);
                    }
                    treeNode.add(node);
                }

                adapter.UpdateTreeNode(treeNode);
                expandlist.setAdapter(adapter);
                expandlist.setOnChildClickListener(new OnChildClickListener() {

                    @Override
                    public boolean onChildClick(ExpandableListView arg0,
                            View arg1, int parent, int children, long arg4) {

                        String str = "parent id:" + String.valueOf(parent)
                                + ",children id:" + String.valueOf(children);
                        Toast.makeText(getApplicationContext(), str, 300)
                                .show();
                        return false;
                    }
                });

            }
        });

        btnSuperTree.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                adapter.RemoveAll();
                adapter.notifyDataSetChanged();
                superAdapter.RemoveAll();
                superAdapter.notifyDataSetChanged();

                List superTreeNode = superAdapter.GetTreeNode();
                for (int i = 0; i < parent.length; i++) // 第一层
                {
                    SuperTreeViewAdaper.SuperTreeNode superNode = new SuperTreeViewAdaper.SuperTreeNode();
                    superNode.parent = parent[i];

                    // 第二层
                    for (int ii = 0; ii < child_grandson.length; ii++) {
                        TreeViewAdapter.TreeNode node = new TreeViewAdapter.TreeNode();
                        node.parent = child_grandson[ii][0][0];// 第二级菜单的标题

                        for (int iii = 0; iii < child_grandson[ii][1].length; iii++) // 第三级菜单
                        {
                            node.childs.add(child_grandson[ii][1][iii]);
                        }
                        superNode.childs.add(node);
                    }
                    superTreeNode.add(superNode);

                }
                superAdapter.UpdateTreeNode(superTreeNode);
                expandlist.setAdapter(superAdapter);
            }

        });
    }
}

运行效果：

点击两层结构：

     

点击三层结构：