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：