Android 多级树形菜单

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：

 

1. static public class TreeNode{
2. Object parent;
3. List<Object> childs=new ArrayList<Object>();
4. }

三级树形菜单可以用如下，子项是二级树形菜单的结构体：

 

1. static public class SuperTreeNode {
2. Object parent;
3. //二级树形菜单的结构体
4. List<TreeViewAdapter.TreeNode> childs = new ArrayList<TreeViewAdapter.TreeNode>();
5. }

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：

1. <?xml version="1.0" encoding="utf-8"?>
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3. android:orientation="vertical" android:layout_width="fill_parent"
4. android:layout_height="fill_parent">
5. <LinearLayout android:id="@+id/LinearLayout01"
6. android:layout_width="wrap_content" android:layout_height="wrap_content">
7. <Button android:layout_height="wrap_content" android:text="两层结构"
8. android:layout_width="160dip" android:id="@+id/btnNormal"></Button>
9. <Button android:layout_height="wrap_content" android:text="三层结构"
10. android:layout_width="160dip" android:id="@+id/btnSuper"></Button>
11. </LinearLayout>
12. <ExpandableListView android:id="@+id/ExpandableListView01"
13. android:layout_width="fill_parent" android:layout_height="fill_parent"></ExpandableListView>
14. </LinearLayout>

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

 

1. package com.testExpandableList;
2. import java.util.List;
3. import android.app.Activity;
4. import android.os.Bundle;
5. import android.util.Log;
6. import android.view.View;
7. import android.widget.Button;
8. import android.widget.ExpandableListView;
9. import android.widget.ExpandableListView.OnChildClickListener;
10. import android.widget.Toast;
11. public class testExpandableList extends Activity {
12. /** Called when the activity is first created. */
13. ExpandableListView expandableList;
14. TreeViewAdapter adapter;
15. SuperTreeViewAdapter superAdapter;
16. Button btnNormal,btnSuper;
17. // Sample data set.  children[i] contains the children (String[]) for groups[i].
18. public String[] groups = { "xxxx好友", "xxxx同学", "xxxxx女人"};
19. public String[][]  child= {
20. { "A君", "B君", "C君", "D君" },
21. { "同学甲", "同学乙", "同学丙"},
22. { "御姐", "萝莉" }
23. };
24. public String[] parent = { "xxxx好友", "xxxx同学"};
25. public String[][][]  child_grandson= {
26. {{"A君"},
27. {"AA","AAA"}},
28. {{"B君"},
29. {"BBB","BBBB","BBBBB"}},
30. {{"C君"},
31. {"CCC","CCCC"}},
32. {{"D君"},
33. {"DDD","DDDD","DDDDD"}},
34. };
35. @Override
36. public void onCreate(Bundle savedInstanceState) {
37. super.onCreate(savedInstanceState);
38. setContentView(R.layout.main);
39. this.setTitle("ExpandableListView练习----hellogv");
40. btnNormal=(Button)this.findViewById(R.id.btnNormal);
41. btnNormal.setOnClickListener(new ClickEvent());
42. btnSuper=(Button)this.findViewById(R.id.btnSuper);
43. btnSuper.setOnClickListener(new ClickEvent());
44. adapter=new TreeViewAdapter(this,TreeViewAdapter.PaddingLeft>>1);
45. superAdapter=new SuperTreeViewAdapter(this,stvClickEvent);
46. expandableList=(ExpandableListView) testExpandableList.this.findViewById(R.id.ExpandableListView01);
47. }
48. class ClickEvent implements View.OnClickListener{
49. @Override
50. public void onClick(View v) {
51. adapter.RemoveAll();
52. adapter.notifyDataSetChanged();
53. superAdapter.RemoveAll();
54. superAdapter.notifyDataSetChanged();
55. if(v==btnNormal)
56. {
57. List<TreeViewAdapter.TreeNode> treeNode = adapter.GetTreeNode();
58. for(int i=0;i<groups.length;i++)
59. {
60. TreeViewAdapter.TreeNode node=new TreeViewAdapter.TreeNode();
61. node.parent=groups[i];
62. for(int ii=0;ii<child[i].length;ii++)
63. {
64. node.childs.add(child[i][ii]);
65. }
66. treeNode.add(node);
67. }
68. adapter.UpdateTreeNode(treeNode);
69. expandableList.setAdapter(adapter);
70. expandableList.setOnChildClickListener(new OnChildClickListener(){
71. @Override
72. public boolean onChildClick(ExpandableListView arg0, View arg1,
73. int parent, int children, long arg4) {
74. String str="parent id:"+String.valueOf(parent)+",children id:"+String.valueOf(children);
75. Toast.makeText(testExpandableList.this, str, 300).show();
76. return false;
77. }
78. });
79. }
80. else if(v==btnSuper){
81. List<SuperTreeViewAdapter.SuperTreeNode> superTreeNode = superAdapter.GetTreeNode();
82. for(int i=0;i<parent.length;i++)//第一层
83. {
84. SuperTreeViewAdapter.SuperTreeNode superNode=new SuperTreeViewAdapter.SuperTreeNode();
85. superNode.parent=parent[i];
86. //第二层
87. for(int ii=0;ii<child_grandson.length;ii++)
88. {
89. TreeViewAdapter.TreeNode node=new TreeViewAdapter.TreeNode();
90. node.parent=child_grandson[ii][0][0];//第二级菜单的标题
91. for(int iii=0;iii<child_grandson[ii][1].length;iii++)//第三级菜单
92. {
93. node.childs.add(child_grandson[ii][1][iii]);
94. }
95. superNode.childs.add(node);
96. }
97. superTreeNode.add(superNode);
98. }
99. superAdapter.UpdateTreeNode(superTreeNode);
100. expandableList.setAdapter(superAdapter);
101. }
102. }
103. }
104. /**
105. * 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
106. */
107. OnChildClickListener stvClickEvent=new OnChildClickListener(){
108. @Override
109. public boolean onChildClick(ExpandableListView parent,
110. View v, int groupPosition, int childPosition,
111. long id) {
112. String str="parent id:"+String.valueOf(groupPosition)+",children id:"+String.valueOf(childPosition);
113. Toast.makeText(testExpandableList.this, str, 300).show();
114. return false;
115. }
116. };
117. }

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

 

1. package com.testExpandableList;
2. import java.util.ArrayList;
3. import java.util.List;
4. import android.content.Context;
5. import android.util.Log;
6. import android.view.Gravity;
7. import android.view.View;
8. import android.view.ViewGroup;
9. import android.widget.AbsListView;
10. import android.widget.BaseExpandableListAdapter;
11. import android.widget.TextView;
12. public class TreeViewAdapter extends BaseExpandableListAdapter{
13. public static final int ItemHeight=48;//每项的高度
14. public static final int PaddingLeft=36;//每项的高度
15. private int myPaddingLeft=0;//如果是由SuperTreeView调用，则作为子项需要往右移
16. static public class TreeNode{
17. Object parent;
18. List<Object> childs=new ArrayList<Object>();
19. }
20. List<TreeNode> treeNodes = new ArrayList<TreeNode>();
21. Context parentContext;
22. public TreeViewAdapter(Context view,int myPaddingLeft)
23. {
24. parentContext=view;
25. this.myPaddingLeft=myPaddingLeft;
26. }
27. public List<TreeNode> GetTreeNode()
28. {
29. return treeNodes;
30. }
31. public void UpdateTreeNode(List<TreeNode> nodes)
32. {
33. treeNodes=nodes;
34. }
35. public void RemoveAll()
36. {
37. treeNodes.clear();
38. }
39. public Object getChild(int groupPosition, int childPosition) {
40. return treeNodes.get(groupPosition).childs.get(childPosition);
41. }
42. public int getChildrenCount(int groupPosition) {
43. return treeNodes.get(groupPosition).childs.size();
44. }
45. static public TextView getTextView(Context context) {
46. AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
47. ViewGroup.LayoutParams.FILL_PARENT, ItemHeight);
48. TextView textView = new TextView(context);
49. textView.setLayoutParams(lp);
50. textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
51. return textView;
52. }
53. public View getChildView(int groupPosition, int childPosition,
54. boolean isLastChild, View convertView, ViewGroup parent) {
55. TextView textView = getTextView(this.parentContext);
56. textView.setText(getChild(groupPosition, childPosition).toString());
57. textView.setPadding(myPaddingLeft+PaddingLeft, 0, 0, 0);
58. return textView;
59. }
60. public View getGroupView(int groupPosition, boolean isExpanded,
61. View convertView, ViewGroup parent) {
62. TextView textView = getTextView(this.parentContext);
63. textView.setText(getGroup(groupPosition).toString());
64. textView.setPadding(myPaddingLeft+(PaddingLeft>>1), 0, 0, 0);
65. return textView;
66. }
67. public long getChildId(int groupPosition, int childPosition) {
68. return childPosition;
69. }
70. public Object getGroup(int groupPosition) {
71. return treeNodes.get(groupPosition).parent;
72. }
73. public int getGroupCount() {
74. return treeNodes.size();
75. }
76. public long getGroupId(int groupPosition) {
77. return groupPosition;
78. }
79. public boolean isChildSelectable(int groupPosition, int childPosition) {
80. return true;
81. }
82. public boolean hasStableIds() {
83. return true;
84. }
85. }

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

 

1. package com.testExpandableList;
2. import java.util.ArrayList;
3. import java.util.List;
4. import com.testExpandableList.TreeViewAdapter.TreeNode;
5. import android.content.Context;
6. import android.view.View;
7. import android.view.ViewGroup;
8. import android.widget.AbsListView;
9. import android.widget.BaseExpandableListAdapter;
10. import android.widget.ExpandableListView;
11. import android.widget.ExpandableListView.OnChildClickListener;
12. import android.widget.ExpandableListView.OnGroupCollapseListener;
13. import android.widget.ExpandableListView.OnGroupExpandListener;
14. import android.widget.TextView;
15. public class SuperTreeViewAdapter extends BaseExpandableListAdapter {
16. static public class SuperTreeNode {
17. Object parent;
18. //二级树形菜单的结构体
19. List<TreeViewAdapter.TreeNode> childs = new ArrayList<TreeViewAdapter.TreeNode>();
20. }
21. private List<SuperTreeNode> superTreeNodes = new ArrayList<SuperTreeNode>();
22. private Context parentContext;
23. private OnChildClickListener stvClickEvent;//外部回调函数
24. public SuperTreeViewAdapter(Context view,OnChildClickListener stvClickEvent) {
25. parentContext = view;
26. this.stvClickEvent=stvClickEvent;
27. }
28. public List<SuperTreeNode> GetTreeNode() {
29. return superTreeNodes;
30. }
31. public void UpdateTreeNode(List<SuperTreeNode> node) {
32. superTreeNodes = node;
33. }
34. public void RemoveAll()
35. {
36. superTreeNodes.clear();
37. }
38. public Object getChild(int groupPosition, int childPosition) {
39. return superTreeNodes.get(groupPosition).childs.get(childPosition);
40. }
41. public int getChildrenCount(int groupPosition) {
42. return superTreeNodes.get(groupPosition).childs.size();
43. }
44. public ExpandableListView getExpandableListView() {
45. AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
46. ViewGroup.LayoutParams.FILL_PARENT, TreeViewAdapter.ItemHeight);
47. ExpandableListView superTreeView = new ExpandableListView(parentContext);
48. superTreeView.setLayoutParams(lp);
49. return superTreeView;
50. }
51. /**
52. * 三层树结构中的第二层是一个ExpandableListView
53. */
54. public View getChildView(int groupPosition, int childPosition,
55. boolean isLastChild, View convertView, ViewGroup parent) {
56. // 是
57. final ExpandableListView treeView = getExpandableListView();
58. final TreeViewAdapter treeViewAdapter = new TreeViewAdapter(this.parentContext,0);
59. List<TreeNode> tmp = treeViewAdapter.GetTreeNode();//临时变量取得TreeViewAdapter的TreeNode集合，可为空
60. final TreeNode treeNode=(TreeNode) getChild(groupPosition, childPosition);
61. tmp.add(treeNode);
62. treeViewAdapter.UpdateTreeNode(tmp);
63. treeView.setAdapter(treeViewAdapter);
64. //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
65. treeView.setOnChildClickListener(this.stvClickEvent);
66. /**
67. * 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
68. */
69. treeView.setOnGroupExpandListener(new OnGroupExpandListener() {
70. @Override
71. public void onGroupExpand(int groupPosition) {
72. AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
73. ViewGroup.LayoutParams.FILL_PARENT,
74. (treeNode.childs.size()+1)*TreeViewAdapter.ItemHeight + 10);
75. treeView.setLayoutParams(lp);
76. }
77. });
78. /**
79. * 第二级菜单回收时设置为标准Item大小
80. */
81. treeView.setOnGroupCollapseListener(new OnGroupCollapseListener() {
82. @Override
83. public void onGroupCollapse(int groupPosition) {
84. AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
85. TreeViewAdapter.ItemHeight);
86. treeView.setLayoutParams(lp);
87. }
88. });
89. treeView.setPadding(TreeViewAdapter.PaddingLeft, 0, 0, 0);
90. return treeView;
91. }
92. /**
93. * 三级树结构中的首层是TextView,用于作为title
94. */
95. public View getGroupView(int groupPosition, boolean isExpanded,
96. View convertView, ViewGroup parent) {
97. TextView textView = TreeViewAdapter.getTextView(this.parentContext);
98. textView.setText(getGroup(groupPosition).toString());
99. textView.setPadding(TreeViewAdapter.PaddingLeft, 0, 0, 0);
100. return textView;
101. }
102. public long getChildId(int groupPosition, int childPosition) {
103. return childPosition;
104. }
105. public Object getGroup(int groupPosition) {
106. return superTreeNodes.get(groupPosition).parent;
107. }
108. public int getGroupCount() {
109. return superTreeNodes.size();
110. }
111. public long getGroupId(int groupPosition) {
112. return groupPosition;
113. }
114. public boolean isChildSelectable(int groupPosition, int childPosition) {
115. return true;
116. }
117. public boolean hasStableIds() {
118. return true;
119. }
120. }

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。