Android---多级树形菜单的实现

叁歲伎倆 2022-08-21 09:57 277阅读 0赞

本文来自 [http://blog.csdn.net/hellogv/][http_blog.csdn.net_hellogv]  ，引用必须注明出处！

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：

![Android---多级树形菜单的实现 - 柠檬加冰 - 柠檬加冰的博客][Android---_ - _ -]

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：

**\[java\]**  [view plain][] [copy][view plain] [print][view plain] [?][view plain]

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：

**\[java\]**  [view plain][] [copy][view plain] [print][view plain] [?][view plain]

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：

**\[xhtml\]**  [view plain][] [copy][view plain] [print][view plain] [?][view plain]

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：

**\[java\]**  [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  **package** com.testExpandableList;  
2.    
3.    
4.  **import** java.util.List;  
5.  **import** android.app.Activity;  
6.  **import** android.os.Bundle;  
7.  **import** android.util.Log;  
8.  **import** android.view.View;  
9.  **import** android.widget.Button;  
10. **import** android.widget.ExpandableListView;  
11. **import** android.widget.ExpandableListView.OnChildClickListener;  
12. **import** android.widget.Toast;  
13.   
14. **public** **class** testExpandableList **extends** Activity \{  
15.     /\*\* Called when the activity is first created. \*/  
16.     ExpandableListView expandableList;  
17.     TreeViewAdapter adapter;  
18.     SuperTreeViewAdapter superAdapter;  
19.     Button btnNormal,btnSuper;  
20.     // Sample data set.  children\[i\] contains the children (String\[\]) for groups\[i\].  
21.     **public** String\[\] groups = \{ "xxxx好友", "xxxx同学", "xxxxx女人"\};  
22.     **public** String\[\]\[\]  child= \{  
23.             \{ "A君", "B君", "C君", "D君" \},  
24.             \{ "同学甲", "同学乙", "同学丙"\},  
25.             \{ "御姐", "萝莉" \}  
26.     \};  
27.       
28.     **public** String\[\] parent = \{ "xxxx好友", "xxxx同学"\};  
29.     **public** String\[\]\[\]\[\]  child\_grandson= \{  
30.             \{ \{ "A君"\},  
31.                 \{ "AA","AAA"\}\},  
32.             \{ \{ "B君"\},  
33.                 \{ "BBB","BBBB","BBBBB"\}\},  
34.             \{ \{ "C君"\},  
35.                 \{ "CCC","CCCC"\}\},  
36.             \{ \{ "D君"\},  
37.                 \{ "DDD","DDDD","DDDDD"\}\},  
38.     \};  
39.       
40.     @Override  
41.     **public** **void** onCreate(Bundle savedInstanceState) \{  
42.         **super**.onCreate(savedInstanceState);  
43.         setContentView(R.layout.main);  
44.         **this**.setTitle("ExpandableListView练习----hellogv");  
45.         btnNormal=(Button)**this**.findViewById(R.id.btnNormal);  
46.         btnNormal.setOnClickListener(**new** ClickEvent());  
47.         btnSuper=(Button)**this**.findViewById(R.id.btnSuper);  
48.         btnSuper.setOnClickListener(**new** ClickEvent());  
49.         adapter=**new** TreeViewAdapter(**this**,TreeViewAdapter.PaddingLeft>>1);  
50.         superAdapter=**new** SuperTreeViewAdapter(**this**,stvClickEvent);  
51.         expandableList=(ExpandableListView) testExpandableList.**this**.findViewById(R.id.ExpandableListView01);  
52.     \}  
53.       
54.     **class** ClickEvent **implements** View.OnClickListener\{  
55.   
56.         @Override  
57.         **public** **void** onClick(View v) \{  
58.             adapter.RemoveAll();  
59.             adapter.notifyDataSetChanged();  
60.             superAdapter.RemoveAll();  
61.             superAdapter.notifyDataSetChanged();  
62.               
63.             **if**(v==btnNormal)  
64.             \{  
65.                 List<TreeViewAdapter.TreeNode> treeNode = adapter.GetTreeNode();  
66.                 **for**(**int** i=0;i<groups.length;i++)  
67.                 \{  
68.                     TreeViewAdapter.TreeNode node=**new** TreeViewAdapter.TreeNode();  
69.                     node.parent=groups\[i\];  
70.                     **for**(**int** ii=0;ii<child\[i\].length;ii++)  
71.                     \{  
72.                         node.childs.add(child\[i\]\[ii\]);  
73.                     \}  
74.                     treeNode.add(node);  
75.                 \}  
76.                   
77.                 adapter.UpdateTreeNode(treeNode);       
78.                 expandableList.setAdapter(adapter);  
79.                 expandableList.setOnChildClickListener(**new** OnChildClickListener()\{  
80.   
81.                     @Override  
82.                     **public** **boolean** onChildClick(ExpandableListView arg0, View arg1,  
83.                             **int** parent, **int** children, **long** arg4) \{  
84.                           
85.                         String str="parent id:"\+String.valueOf(parent)+",children id:"\+String.valueOf(children);  
86.                         Toast.makeText(testExpandableList.**this**, str, 300).show();  
87.                         **return** **false**;  
88.                     \}  
89.                 \});  
90.             \}  
91.             **else** **if**(v==btnSuper)\{  
92.                 List<SuperTreeViewAdapter.SuperTreeNode> superTreeNode = superAdapter.GetTreeNode();  
93.                 **for**(**int** i=0;i<parent.length;i++)//第一层  
94.                 \{  
95.                     SuperTreeViewAdapter.SuperTreeNode superNode=**new** SuperTreeViewAdapter.SuperTreeNode();  
96.                     superNode.parent=parent\[i\];  
97.                       
98.                     //第二层  
99.                     **for**(**int** ii=0;ii<child\_grandson.length;ii++)  
100.                     \{  
101.                         TreeViewAdapter.TreeNode node=**new** TreeViewAdapter.TreeNode();  
102.                         node.parent=child\_grandson\[ii\]\[0\]\[0\];//第二级菜单的标题  
103.                           
104.                         **for**(**int** iii=0;iii<child\_grandson\[ii\]\[1\].length;iii++)//第三级菜单  
105.                         \{  
106.                             node.childs.add(child\_grandson\[ii\]\[1\]\[iii\]);  
107.                         \}  
108.                         superNode.childs.add(node);  
109.                     \}  
110.                     superTreeNode.add(superNode);  
111.                       
112.                 \}  
113.                 superAdapter.UpdateTreeNode(superTreeNode);  
114.                 expandableList.setAdapter(superAdapter);  
115.             \}  
116.         \}  
117.     \}  
118.   
119.     /\*\* 
120.      \* 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 
121.      \*/  
122.     OnChildClickListener stvClickEvent=**new** OnChildClickListener()\{  
123.   
124.         @Override  
125.         **public** **boolean** onChildClick(ExpandableListView parent,  
126.                 View v, **int** groupPosition, **int** childPosition,  
127.                 **long** id) \{  
128.             String str="parent id:"\+String.valueOf(groupPosition)+",children id:"\+String.valueOf(childPosition);  
129.             Toast.makeText(testExpandableList.**this**, str, 300).show();  
130.               
131.             **return** **false**;  
132.         \}  
133.           
134.     \};  
135. \}

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

**\[java\]**  [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  **package** com.testExpandableList;  
2.    
3.  **import** java.util.ArrayList;  
4.  **import** java.util.List;  
5.  **import** android.content.Context;  
6.  **import** android.util.Log;  
7.  **import** android.view.Gravity;  
8.  **import** android.view.View;  
9.  **import** android.view.ViewGroup;  
10. **import** android.widget.AbsListView;  
11. **import** android.widget.BaseExpandableListAdapter;  
12. **import** android.widget.TextView;  
13.   
14.   
15. **public** **class** TreeViewAdapter **extends** BaseExpandableListAdapter\{  
16.     **public** **static** **final** **int** ItemHeight=48;//每项的高度  
17.     **public** **static** **final** **int** PaddingLeft=36;//每项的高度  
18.     **private** **int** myPaddingLeft=0;//如果是由SuperTreeView调用，则作为子项需要往右移  
19.   
20.     **static** **public** **class** TreeNode\{  
21.         Object parent;  
22.         List<Object> childs=**new** ArrayList<Object>();  
23.     \}  
24.       
25.     List<TreeNode> treeNodes = **new** ArrayList<TreeNode>();  
26.     Context parentContext;  
27.       
28.     **public** TreeViewAdapter(Context view,**int** myPaddingLeft)  
29.     \{  
30.         parentContext=view;  
31.         **this**.myPaddingLeft=myPaddingLeft;  
32.     \}  
33.       
34.     **public** List<TreeNode> GetTreeNode()  
35.     \{  
36.         **return** treeNodes;  
37.     \}  
38.       
39.     **public** **void** UpdateTreeNode(List<TreeNode> nodes)  
40.     \{  
41.         treeNodes=nodes;  
42.     \}  
43.       
44.     **public** **void** RemoveAll()  
45.     \{  
46.         treeNodes.clear();  
47.     \}  
48.       
49.     **public** Object getChild(**int** groupPosition, **int** childPosition) \{  
50.         **return** treeNodes.get(groupPosition).childs.get(childPosition);  
51.     \}  
52.   
53.     **public** **int** getChildrenCount(**int** groupPosition) \{  
54.         **return** treeNodes.get(groupPosition).childs.size();  
55.     \}  
56.   
57.     **static** **public** TextView getTextView(Context context) \{  
58.         AbsListView.LayoutParams lp = **new** AbsListView.LayoutParams(  
59.                 ViewGroup.LayoutParams.FILL\_PARENT, ItemHeight);  
60.   
61.         TextView textView = **new** TextView(context);  
62.         textView.setLayoutParams(lp);  
63.         textView.setGravity(Gravity.CENTER\_VERTICAL | Gravity.LEFT);  
64.         **return** textView;  
65.     \}  
66.   
67.     **public** View getChildView(**int** groupPosition, **int** childPosition,  
68.             **boolean** isLastChild, View convertView, ViewGroup parent) \{  
69.         TextView textView = getTextView(**this**.parentContext);  
70.         textView.setText(getChild(groupPosition, childPosition).toString());  
71.         textView.setPadding(myPaddingLeft+PaddingLeft, 0, 0, 0);  
72.         **return** textView;  
73.     \}  
74.   
75.     **public** View getGroupView(**int** groupPosition, **boolean** isExpanded,  
76.             View convertView, ViewGroup parent) \{  
77.         TextView textView = getTextView(**this**.parentContext);  
78.         textView.setText(getGroup(groupPosition).toString());  
79.         textView.setPadding(myPaddingLeft+(PaddingLeft>>1), 0, 0, 0);  
80.         **return** textView;  
81.     \}  
82.   
83.     **public** **long** getChildId(**int** groupPosition, **int** childPosition) \{  
84.         **return** childPosition;  
85.     \}  
86.   
87.     **public** Object getGroup(**int** groupPosition) \{  
88.         **return** treeNodes.get(groupPosition).parent;  
89.     \}  
90.   
91.     **public** **int** getGroupCount() \{  
92.         **return** treeNodes.size();  
93.     \}  
94.   
95.     **public** **long** getGroupId(**int** groupPosition) \{  
96.         **return** groupPosition;  
97.     \}  
98.   
99.     **public** **boolean** isChildSelectable(**int** groupPosition, **int** childPosition) \{  
100.         **return** **true**;  
101.     \}  
102.   
103.     **public** **boolean** hasStableIds() \{  
104.         **return** **true**;  
105.     \}  
106. \}

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

**\[java\]**  [view plain][] [copy][view plain] [print][view plain] [?][view plain]

1.  **package** com.testExpandableList;  
2.    
3.  **import** java.util.ArrayList;  
4.  **import** java.util.List;  
5.  **import** com.testExpandableList.TreeViewAdapter.TreeNode;  
6.  **import** android.content.Context;  
7.  **import** android.view.View;  
8.  **import** android.view.ViewGroup;  
9.  **import** android.widget.AbsListView;  
10. **import** android.widget.BaseExpandableListAdapter;  
11. **import** android.widget.ExpandableListView;  
12. **import** android.widget.ExpandableListView.OnChildClickListener;  
13. **import** android.widget.ExpandableListView.OnGroupCollapseListener;  
14. **import** android.widget.ExpandableListView.OnGroupExpandListener;  
15. **import** android.widget.TextView;  
16.   
17. **public** **class** SuperTreeViewAdapter **extends** BaseExpandableListAdapter \{  
18.   
19.     **static** **public** **class** SuperTreeNode \{  
20.         Object parent;  
21.         //二级树形菜单的结构体  
22.         List<TreeViewAdapter.TreeNode> childs = **new** ArrayList<TreeViewAdapter.TreeNode>();  
23.     \}  
24.   
25.     **private** List<SuperTreeNode> superTreeNodes = **new** ArrayList<SuperTreeNode>();  
26.     **private** Context parentContext;  
27.     **private** OnChildClickListener stvClickEvent;//外部回调函数  
28.       
29.     **public** SuperTreeViewAdapter(Context view,OnChildClickListener stvClickEvent) \{  
30.         parentContext = view;  
31.         **this**.stvClickEvent=stvClickEvent;  
32.     \}  
33.   
34.     **public** List<SuperTreeNode> GetTreeNode() \{  
35.         **return** superTreeNodes;  
36.     \}  
37.   
38.     **public** **void** UpdateTreeNode(List<SuperTreeNode> node) \{  
39.         superTreeNodes = node;  
40.     \}  
41.       
42.     **public** **void** RemoveAll()  
43.     \{  
44.         superTreeNodes.clear();  
45.     \}  
46.       
47.     **public** Object getChild(**int** groupPosition, **int** childPosition) \{  
48.         **return** superTreeNodes.get(groupPosition).childs.get(childPosition);  
49.     \}  
50.   
51.     **public** **int** getChildrenCount(**int** groupPosition) \{  
52.         **return** superTreeNodes.get(groupPosition).childs.size();  
53.     \}  
54.   
55.     **public** ExpandableListView getExpandableListView() \{  
56.         AbsListView.LayoutParams lp = **new** AbsListView.LayoutParams(  
57.                 ViewGroup.LayoutParams.FILL\_PARENT, TreeViewAdapter.ItemHeight);  
58.         ExpandableListView superTreeView = **new** ExpandableListView(parentContext);  
59.         superTreeView.setLayoutParams(lp);  
60.         **return** superTreeView;  
61.     \}  
62.   
63.     /\*\* 
64.      \* 三层树结构中的第二层是一个ExpandableListView 
65.      \*/   
66.     **public** View getChildView(**int** groupPosition, **int** childPosition,  
67.             **boolean** isLastChild, View convertView, ViewGroup parent) \{  
68.         // 是   
69.         **final** ExpandableListView treeView = getExpandableListView();  
70.         **final** TreeViewAdapter treeViewAdapter = **new** TreeViewAdapter(**this**.parentContext,0);  
71.         List<TreeNode> tmp = treeViewAdapter.GetTreeNode();//临时变量取得TreeViewAdapter的TreeNode集合，可为空  
72.         **final** TreeNode treeNode=(TreeNode) getChild(groupPosition, childPosition);  
73.         tmp.add(treeNode);  
74.         treeViewAdapter.UpdateTreeNode(tmp);  
75.         treeView.setAdapter(treeViewAdapter);  
76.           
77.         //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  
78.         treeView.setOnChildClickListener(**this**.stvClickEvent);  
79.           
80.         /\*\* 
81.          \* 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 
82.          \*/  
83.         treeView.setOnGroupExpandListener(**new** OnGroupExpandListener() \{  
84.             @Override  
85.             **public** **void** onGroupExpand(**int** groupPosition) \{  
86.                   
87.                 AbsListView.LayoutParams lp = **new** AbsListView.LayoutParams(  
88.                         ViewGroup.LayoutParams.FILL\_PARENT,  
89.                         (treeNode.childs.size()+1)\*TreeViewAdapter.ItemHeight + 10);  
90.                 treeView.setLayoutParams(lp);  
91.             \}  
92.         \});  
93.           
94.         /\*\* 
95.          \* 第二级菜单回收时设置为标准Item大小 
96.          \*/  
97.         treeView.setOnGroupCollapseListener(**new** OnGroupCollapseListener() \{  
98.             @Override  
99.             **public** **void** onGroupCollapse(**int** groupPosition) \{  
100.                   
101.                 AbsListView.LayoutParams lp = **new** AbsListView.LayoutParams(ViewGroup.LayoutParams.FILL\_PARENT,  
102.                         TreeViewAdapter.ItemHeight);  
103.                 treeView.setLayoutParams(lp);  
104.             \}  
105.         \});  
106.         treeView.setPadding(TreeViewAdapter.PaddingLeft, 0, 0, 0);  
107.         **return** treeView;  
108.     \}  
109.   
110.     /\*\* 
111.      \* 三级树结构中的首层是TextView,用于作为title 
112.      \*/  
113.     **public** View getGroupView(**int** groupPosition, **boolean** isExpanded,  
114.             View convertView, ViewGroup parent) \{  
115.         TextView textView = TreeViewAdapter.getTextView(**this**.parentContext);  
116.         textView.setText(getGroup(groupPosition).toString());  
117.         textView.setPadding(TreeViewAdapter.PaddingLeft, 0, 0, 0);  
118.         **return** textView;  
119.     \}  
120.   
121.     **public** **long** getChildId(**int** groupPosition, **int** childPosition) \{  
122.         **return** childPosition;  
123.     \}  
124.   
125.     **public** Object getGroup(**int** groupPosition) \{  
126.         **return** superTreeNodes.get(groupPosition).parent;  
127.     \}  
128.   
129.     **public** **int** getGroupCount() \{  
130.         **return** superTreeNodes.size();  
131.     \}  
132.   
133.     **public** **long** getGroupId(**int** groupPosition) \{  
134.         **return** groupPosition;  
135.     \}  
136.   
137.     **public** **boolean** isChildSelectable(**int** groupPosition, **int** childPosition) \{  
138.         **return** **true**;  
139.     \}  
140.   
141.     **public** **boolean** hasStableIds() \{  
142.         **return** **true**;  
143.     \}  
144. \}

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。

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