Android提高十七篇之多级树形菜单的实现

http://blog.csdn.net/hellogv/archive/2011/01/06/6120133.aspx

 

在Android里要实现树形菜单，都是用ExpandableList(也有高手自己继承ListView或者LinearLayout来做)，但是ExpandableList一般只能实现2级树形菜单......本文也依然使用ExpandableList，但是要实现的是3级树形菜单。本文程序运行效果图：

当用BaseExpandableListAdapter来实现二级树形菜单时，父项(getGroupView())和子项(getChildView())都是使用TextView。当要实现三级树形菜单时，子项(getChildView())就必须使用ExpandableList了.......另外还要定义结构体来方便调用三级树形的数据，二级树形菜单可以用如下：

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

 

三级树形菜单可以用如下，子项是二级树形菜单的结构体：

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

 

实现三级树形菜单有两点要注意的：

1、第二级也是个树形菜单，因此必须在第二级项目展开/回收时设置足够的空间来完全显示二级树形菜单；

2、在实现三级树形菜单时，发现菜单的方法都是用不了(如OnChildClickListener、OnGroupClickListener等)，因此要获得选中的数据就必须在外部定义好回调函数，然后在第二级生成二级树形菜单时回调这个外部函数。

PS：本文在解决No.2关键点的时候，只能取得第三级选中的序号.....而第一，第二级依然无法获取其序号。

main.xml源码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <LinearLayout android:id="@+id/LinearLayout01"
        android:layout_width="wrap_content" android:layout_height="wrap_content">
        <Button android:layout_height="wrap_content" android:text="两层结构"
            android:layout_width="160dip" android:id="@+id/btnNormal"></Button>
        <Button android:layout_height="wrap_content" android:text="三层结构"
            android:layout_width="160dip" android:id="@+id/btnSuper"></Button>
    </LinearLayout>
    <ExpandableListView android:id="@+id/ExpandableListView01"
        android:layout_width="fill_parent" android:layout_height="fill_parent"></ExpandableListView>
</LinearLayout>

 

testExpandableList.java是主类，调用其他工具类，源码如下：

package com.testExpandableList;


import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.Toast;

public class testExpandableList extends Activity {
    /** Called when the activity is first created. */
    ExpandableListView expandableList;
    TreeViewAdapter adapter;
    SuperTreeViewAdapter superAdapter;
    Button btnNormal,btnSuper;
    // Sample data set.  children[i] contains the children (String[]) for groups[i].
    public String[] groups = { "xxxx好友", "xxxx同学", "xxxxx女人"};
    public String[][]  child= {
            { "A君", "B君", "C君", "D君" },
            { "同学甲", "同学乙", "同学丙"},
            { "御姐", "萝莉" }
    };

    public String[] parent = { "xxxx好友", "xxxx同学"};
    public String[][][]  child_grandson= {
            {{"A君"},
                {"AA","AAA"}},
            {{"B君"},
                {"BBB","BBBB","BBBBB"}},
            {{"C君"},
                {"CCC","CCCC"}},
            {{"D君"},
                {"DDD","DDDD","DDDDD"}},
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.setTitle("ExpandableListView练习----hellogv");
        btnNormal=(Button)this.findViewById(R.id.btnNormal);
        btnNormal.setOnClickListener(new ClickEvent());
        btnSuper=(Button)this.findViewById(R.id.btnSuper);
        btnSuper.setOnClickListener(new ClickEvent());
        adapter=new TreeViewAdapter(this,TreeViewAdapter.PaddingLeft>>1);
        superAdapter=new SuperTreeViewAdapter(this,stvClickEvent);
        expandableList=(ExpandableListView) testExpandableList.this.findViewById(R.id.ExpandableListView01);
    }

    class ClickEvent implements View.OnClickListener{

        @Override
        public void onClick(View v) {
            adapter.RemoveAll();
            adapter.notifyDataSetChanged();
            superAdapter.RemoveAll();
            superAdapter.notifyDataSetChanged();

            if(v==btnNormal)
            {
                List<TreeViewAdapter.TreeNode> treeNode = adapter.GetTreeNode();
                for(int i=0;i<groups.length;i++)
                {
                    TreeViewAdapter.TreeNode node=new TreeViewAdapter.TreeNode();
                    node.parent=groups[i];
                    for(int ii=0;ii<child[i].length;ii++)
                    {
                        node.childs.add(child[i][ii]);
                    }
                    treeNode.add(node);
                }

                adapter.UpdateTreeNode(treeNode);
                expandableList.setAdapter(adapter);
                expandableList.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(testExpandableList.this, str, 300).show();
                        return false;
                    }
                });
            }
            else if(v==btnSuper){
                List<SuperTreeViewAdapter.SuperTreeNode> superTreeNode = superAdapter.GetTreeNode();
                for(int i=0;i<parent.length;i++)//第一层
                {
                    SuperTreeViewAdapter.SuperTreeNode superNode=new SuperTreeViewAdapter.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);
                expandableList.setAdapter(superAdapter);
            }
        }
    }

    /**
     * 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(testExpandableList.this, str, 300).show();

            return false;
        }

    };
}

 

TreeViewAdapter.java是实现二级树形菜单的工具类，源码如下：

package com.testExpandableList;

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;//每项的高度
    public static final int PaddingLeft=36;//每项的高度
    private int myPaddingLeft=0;//如果是由SuperTreeView调用，则作为子项需要往右移

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

    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;
    }
}

 

SuperTreeViewAdapter.java是实现三级树形菜单的工具类，会用到TreeViewAdapter.java，源码如下：

package com.testExpandableList;

import java.util.ArrayList;
import java.util.List;
import com.testExpandableList.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 SuperTreeViewAdapter extends BaseExpandableListAdapter {

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

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

    public SuperTreeViewAdapter(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;
    }
}

 

总结，使用ExpandableList实现三级树形菜单时有些bug不好解决，而且定义三维数组的时候也要倍加小心......所以尽量把数据化简来使用二级树形菜单。