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：

view plain copy to clipboard print ? 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：

view plain copy to clipboard print ? 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：

view plain copy to clipboard print ? <?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：

view plain copy to clipboard print ? 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：

view plain copy to clipboard print ? 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：

view plain copy to clipboard print ? 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。