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。