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Android提高十七篇之多级树形菜单的实现

 
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本文来自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：

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 plainprint?
  1. staticpublicclassTreeNode{
  2. Objectparent;
  3. List<Object>childs=newArrayList<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：

view plainprint?
  1. staticpublicclassSuperTreeNode{
  2. Objectparent;
  3. //二级树形菜单的结构体
  4. List<TreeViewAdapter.TreeNode>childs=newArrayList<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：

view plainprint?
  1. <?xmlversion="1.0"encoding="utf-8"?>
  2. <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
  3. android:orientation="vertical"android:layout_width="fill_parent"
  4. android:layout_height="fill_parent">
  5. <LinearLayoutandroid:id="@+id/LinearLayout01"
  6. android:layout_width="wrap_content"android:layout_height="wrap_content">
  7. <Buttonandroid:layout_height="wrap_content"android:text="两层结构"
  8. android:layout_width="160dip"android:id="@+id/btnNormal"></Button>
  9. <Buttonandroid:layout_height="wrap_content"android:text="三层结构"
  10. android:layout_width="160dip"android:id="@+id/btnSuper"></Button>
  11. </LinearLayout>
  12. <ExpandableListViewandroid: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：

view plainprint?
  1. packagecom.testExpandableList;
  4. importjava.util.List;
  5. importandroid.app.Activity;
  6. importandroid.os.Bundle;
  7. importandroid.util.Log;
  8. importandroid.view.View;
  9. importandroid.widget.Button;
  10. importandroid.widget.ExpandableListView;
  11. importandroid.widget.ExpandableListView.OnChildClickListener;
  12. importandroid.widget.Toast;
  14. publicclasstestExpandableListextendsActivity{
  15. /**Calledwhentheactivityisfirstcreated.*/
  16. ExpandableListViewexpandableList;
  17. TreeViewAdapteradapter;
  18. SuperTreeViewAdaptersuperAdapter;
  19. ButtonbtnNormal,btnSuper;
  20. //Sampledataset.children[i]containsthechildren(String[])forgroups[i].
  21. publicString[]groups={"xxxx好友","xxxx同学","xxxxx女人"};
  22. publicString[][]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. };
  28. publicString[]parent={"xxxx好友","xxxx同学"};
  29. publicString[][][]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. };
  40. @Override
  41. publicvoidonCreate(BundlesavedInstanceState){
  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(newClickEvent());
  47. btnSuper=(Button)this.findViewById(R.id.btnSuper);
  48. btnSuper.setOnClickListener(newClickEvent());
  49. adapter=newTreeViewAdapter(this,TreeViewAdapter.PaddingLeft>>1);
  50. superAdapter=newSuperTreeViewAdapter(this,stvClickEvent);
  51. expandableList=(ExpandableListView)testExpandableList.this.findViewById(R.id.ExpandableListView01);
  52. }
  54. classClickEventimplementsView.OnClickListener{
  56. @Override
  57. publicvoidonClick(Viewv){
  58. adapter.RemoveAll();
  59. adapter.notifyDataSetChanged();
  60. superAdapter.RemoveAll();
  61. superAdapter.notifyDataSetChanged();
  63. if(v==btnNormal)
  64. {
  65. List<TreeViewAdapter.TreeNode>treeNode=adapter.GetTreeNode();
  66. for(inti=0;i<groups.length;i++)
  67. {
  68. TreeViewAdapter.TreeNodenode=newTreeViewAdapter.TreeNode();
  69. node.parent=groups[i];
  70. for(intii=0;ii<child[i].length;ii++)
  71. {
  72. node.childs.add(child[i][ii]);
  73. }
  74. treeNode.add(node);
  75. }
  77. adapter.UpdateTreeNode(treeNode);
  78. expandableList.setAdapter(adapter);
  79. expandableList.setOnChildClickListener(newOnChildClickListener(){
  81. @Override
  82. publicbooleanonChildClick(ExpandableListViewarg0,Viewarg1,
  83. intparent,intchildren,longarg4){
  85. Stringstr="parentid:"+String.valueOf(parent)+",childrenid:"+String.valueOf(children);
  86. Toast.makeText(testExpandableList.this,str,300).show();
  87. returnfalse;
  88. }
  89. });
  90. }
  91. elseif(v==btnSuper){
  92. List<SuperTreeViewAdapter.SuperTreeNode>superTreeNode=superAdapter.GetTreeNode();
  93. for(inti=0;i<parent.length;i++)//第一层
  94. {
  95. SuperTreeViewAdapter.SuperTreeNodesuperNode=newSuperTreeViewAdapter.SuperTreeNode();
  96. superNode.parent=parent[i];
  98. //第二层
  99. for(intii=0;ii<child_grandson.length;ii++)
  100. {
  101. TreeViewAdapter.TreeNodenode=newTreeViewAdapter.TreeNode();
  102. node.parent=child_grandson[ii][0][0];//第二级菜单的标题
  104. for(intiii=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);
  112. }
  113. superAdapter.UpdateTreeNode(superTreeNode);
  114. expandableList.setAdapter(superAdapter);
  115. }
  116. }
  117. }
  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. OnChildClickListenerstvClickEvent=newOnChildClickListener(){
  124. @Override
  125. publicbooleanonChildClick(ExpandableListViewparent,
  126. Viewv,intgroupPosition,intchildPosition,
  127. longid){
  128. Stringstr="parentid:"+String.valueOf(groupPosition)+",childrenid:"+String.valueOf(childPosition);
  129. Toast.makeText(testExpandableList.this,str,300).show();
  131. returnfalse;
  132. }
  134. };
  135. }

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

view plainprint?
  1. packagecom.testExpandableList;
  3. importjava.util.ArrayList;
  4. importjava.util.List;
  5. importandroid.content.Context;
  6. importandroid.util.Log;
  7. importandroid.view.Gravity;
  8. importandroid.view.View;
  9. importandroid.view.ViewGroup;
  10. importandroid.widget.AbsListView;
  11. importandroid.widget.BaseExpandableListAdapter;
  12. importandroid.widget.TextView;
  15. publicclassTreeViewAdapterextendsBaseExpandableListAdapter{
  16. publicstaticfinalintItemHeight=48;//每项的高度
  17. publicstaticfinalintPaddingLeft=36;//每项的高度
  18. privateintmyPaddingLeft=0;//如果是由SuperTreeView调用，则作为子项需要往右移
  20. staticpublicclassTreeNode{
  21. Objectparent;
  22. List<Object>childs=newArrayList<Object>();
  23. }
  25. List<TreeNode>treeNodes=newArrayList<TreeNode>();
  26. ContextparentContext;
  28. publicTreeViewAdapter(Contextview,intmyPaddingLeft)
  29. {
  30. parentContext=view;
  31. this.myPaddingLeft=myPaddingLeft;
  32. }
  34. publicList<TreeNode>GetTreeNode()
  35. {
  36. returntreeNodes;
  37. }
  39. publicvoidUpdateTreeNode(List<TreeNode>nodes)
  40. {
  41. treeNodes=nodes;
  42. }
  44. publicvoidRemoveAll()
  45. {
  46. treeNodes.clear();
  47. }
  49. publicObjectgetChild(intgroupPosition,intchildPosition){
  50. returntreeNodes.get(groupPosition).childs.get(childPosition);
  51. }
  53. publicintgetChildrenCount(intgroupPosition){
  54. returntreeNodes.get(groupPosition).childs.size();
  55. }
  57. staticpublicTextViewgetTextView(Contextcontext){
  58. AbsListView.LayoutParamslp=newAbsListView.LayoutParams(
  59. ViewGroup.LayoutParams.FILL_PARENT,ItemHeight);
  61. TextViewtextView=newTextView(context);
  62. textView.setLayoutParams(lp);
  63. textView.setGravity(Gravity.CENTER_VERTICAL|Gravity.LEFT);
  64. returntextView;
  65. }
  67. publicViewgetChildView(intgroupPosition,intchildPosition,
  68. booleanisLastChild,ViewconvertView,ViewGroupparent){
  69. TextViewtextView=getTextView(this.parentContext);
  70. textView.setText(getChild(groupPosition,childPosition).toString());
  71. textView.setPadding(myPaddingLeft+PaddingLeft,0,0,0);
  72. returntextView;
  73. }
  75. publicViewgetGroupView(intgroupPosition,booleanisExpanded,
  76. ViewconvertView,ViewGroupparent){
  77. TextViewtextView=getTextView(this.parentContext);
  78. textView.setText(getGroup(groupPosition).toString());
  79. textView.setPadding(myPaddingLeft+(PaddingLeft>>1),0,0,0);
  80. returntextView;
  81. }
  83. publiclonggetChildId(intgroupPosition,intchildPosition){
  84. returnchildPosition;
  85. }
  87. publicObjectgetGroup(intgroupPosition){
  88. returntreeNodes.get(groupPosition).parent;
  89. }
  91. publicintgetGroupCount(){
  92. returntreeNodes.size();
  93. }
  95. publiclonggetGroupId(intgroupPosition){
  96. returngroupPosition;
  97. }
  99. publicbooleanisChildSelectable(intgroupPosition,intchildPosition){
  100. returntrue;
  101. }
  103. publicbooleanhasStableIds(){
  104. returntrue;
  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：

view plainprint?
  1. packagecom.testExpandableList;
  3. importjava.util.ArrayList;
  4. importjava.util.List;
  5. importcom.testExpandableList.TreeViewAdapter.TreeNode;
  6. importandroid.content.Context;
  7. importandroid.view.View;
  8. importandroid.view.ViewGroup;
  9. importandroid.widget.AbsListView;
  10. importandroid.widget.BaseExpandableListAdapter;
  11. importandroid.widget.ExpandableListView;
  12. importandroid.widget.ExpandableListView.OnChildClickListener;
  13. importandroid.widget.ExpandableListView.OnGroupCollapseListener;
  14. importandroid.widget.ExpandableListView.OnGroupExpandListener;
  15. importandroid.widget.TextView;
  17. publicclassSuperTreeViewAdapterextendsBaseExpandableListAdapter{
  19. staticpublicclassSuperTreeNode{
  20. Objectparent;
  21. //二级树形菜单的结构体
  22. List<TreeViewAdapter.TreeNode>childs=newArrayList<TreeViewAdapter.TreeNode>();
  23. }
  25. privateList<SuperTreeNode>superTreeNodes=newArrayList<SuperTreeNode>();
  26. privateContextparentContext;
  27. privateOnChildClickListenerstvClickEvent;//外部回调函数
  29. publicSuperTreeViewAdapter(Contextview,OnChildClickListenerstvClickEvent){
  30. parentContext=view;
  31. this.stvClickEvent=stvClickEvent;
  32. }
  34. publicList<SuperTreeNode>GetTreeNode(){
  35. returnsuperTreeNodes;
  36. }
  38. publicvoidUpdateTreeNode(List<SuperTreeNode>node){
  39. superTreeNodes=node;
  40. }
  42. publicvoidRemoveAll()
  43. {
  44. superTreeNodes.clear();
  45. }
  47. publicObjectgetChild(intgroupPosition,intchildPosition){
  48. returnsuperTreeNodes.get(groupPosition).childs.get(childPosition);
  49. }
  51. publicintgetChildrenCount(intgroupPosition){
  52. returnsuperTreeNodes.get(groupPosition).childs.size();
  53. }
  55. publicExpandableListViewgetExpandableListView(){
  56. AbsListView.LayoutParamslp=newAbsListView.LayoutParams(
  57. ViewGroup.LayoutParams.FILL_PARENT,TreeViewAdapter.ItemHeight);
  58. ExpandableListViewsuperTreeView=newExpandableListView(parentContext);
  59. superTreeView.setLayoutParams(lp);
  60. returnsuperTreeView;
  61. }
  63. /**
  64. *三层树结构中的第二层是一个ExpandableListView
  65. */
  66. publicViewgetChildView(intgroupPosition,intchildPosition,
  67. booleanisLastChild,ViewconvertView,ViewGroupparent){
  68. //是
  69. finalExpandableListViewtreeView=getExpandableListView();
  70. finalTreeViewAdaptertreeViewAdapter=newTreeViewAdapter(this.parentContext,0);
  71. List<TreeNode>tmp=treeViewAdapter.GetTreeNode();//临时变量取得TreeViewAdapter的TreeNode集合，可为空
  72. finalTreeNodetreeNode=(TreeNode)getChild(groupPosition,childPosition);
  73. tmp.add(treeNode);
  74. treeViewAdapter.UpdateTreeNode(tmp);
  75. treeView.setAdapter(treeViewAdapter);
  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);
  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(newOnGroupExpandListener(){
  84. @Override
  85. publicvoidonGroupExpand(intgroupPosition){
  87. AbsListView.LayoutParamslp=newAbsListView.LayoutParams(
  88. ViewGroup.LayoutParams.FILL_PARENT,
  89. (treeNode.childs.size()+1)*TreeViewAdapter.ItemHeight+10);
  90. treeView.setLayoutParams(lp);
  91. }
  92. });
  94. /**
  95. *第二级菜单回收时设置为标准Item大小
  96. */
  97. treeView.setOnGroupCollapseListener(newOnGroupCollapseListener(){
  98. @Override
  99. publicvoidonGroupCollapse(intgroupPosition){
  101. AbsListView.LayoutParamslp=newAbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
  102. TreeViewAdapter.ItemHeight);
  103. treeView.setLayoutParams(lp);
  104. }
  105. });
  106. treeView.setPadding(TreeViewAdapter.PaddingLeft,0,0,0);
  107. returntreeView;
  108. }
  110. /**
  111. *三级树结构中的首层是TextView,用于作为title
  112. */
  113. publicViewgetGroupView(intgroupPosition,booleanisExpanded,
  114. ViewconvertView,ViewGroupparent){
  115. TextViewtextView=TreeViewAdapter.getTextView(this.parentContext);
  116. textView.setText(getGroup(groupPosition).toString());
  117. textView.setPadding(TreeViewAdapter.PaddingLeft,0,0,0);
  118. returntextView;
  119. }
  121. publiclonggetChildId(intgroupPosition,intchildPosition){
  122. returnchildPosition;
  123. }
  125. publicObjectgetGroup(intgroupPosition){
  126. returnsuperTreeNodes.get(groupPosition).parent;
  127. }
  129. publicintgetGroupCount(){
  130. returnsuperTreeNodes.size();
  131. }
  133. publiclonggetGroupId(intgroupPosition){
  134. returngroupPosition;
  135. }
  137. publicbooleanisChildSelectable(intgroupPosition,intchildPosition){
  138. returntrue;
  139. }
  141. publicbooleanhasStableIds(){
  142. returntrue;
  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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