• Android 多级菜单实现


      在Android里要实现树形菜单,都是用ExpandableList,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。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 Code
    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 Code
    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。
    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。

    <?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>



    java是主类,调用其他工具类,源码如下:
    View Code
    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;
    }

    };
    }

      实现二级树形菜单的工具类,源码如下:

    View Code
    package eoe.demo; 

    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;
    }
    }


      实现三级树形菜单的工具类

    View Code
    package eoe.demo; 

    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) {
    //
    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;
    }
    }



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  • 原文地址:https://www.cnblogs.com/lyp3314/p/2264022.html
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