android列表控件实现展开、收缩功能

最近在做一个rss阅读器，我看了一看别人做的阅读器中的lisview可以伸缩，展开，我就在网上搜索了一下。果然让我找到，下面就我找到的一个小例子，给大家分享一下。 

activitymain .java

package com.android;


import android.app.expandablelistactivity;
import android.os.bundle;
import android.view.contextmenu;
import android.view.menuitem;
import android.view.view;
import android.view.contextmenu.contextmenuinfo;
import android.widget.expandablelistadapter;
import android.widget.expandablelistview;
import android.widget.textview;
import android.widget.toast;
import android.widget.expandablelistview.expandablelistcontextmenuinfo;

public class activitymain extends expandablelistactivity {

 
 private expandablelistadapter madapter;
 
 @override
 public void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  this.settitle("expandablelist");
  madapter = new myexpandablelistadapter(this);
  setlistadapter(madapter);
  registerforcontextmenu(this.getexpandablelistview());
 }

 
 //为列表的每一项创建上下文菜单（即长按后 呼出的菜单）
 @override
 public void oncreatecontextmenu(contextmenu menu, view v,
 contextmenuinfo menuinfo) {
 menu.setheadertitle("contexmenu");
 menu.add(0,0,0,"contextmenu");
 }

 //单击上下文菜单后的逻辑
 @override
 public boolean oncontextitemselected(menuitem item) {
 
 expandablelistcontextmenuinfo info = (expandablelistcontextmenuinfo)item.getmenuinfo();
 string title = ((textview) info.targetview).gettext().tostring();
 
 int type =expandablelistview.getpackedpositiontype(info.packedposition);
 if(type == expandablelistview.packed_position_type_child)
 {
 
 int grouppos = expandablelistview.getpackedpositiongroup(info.packedposition);
 int childpos = expandablelistview.getpackedpositionchild(info.packedposition);
 toast.maketext(this, title+"-group index"+grouppos+"child index:"+childpos,
  toast.length_short).show();
 return true;
 }
 return false;
 }

myexpandablelistadapter.java

package com.android;

import android.content.context;
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 myexpandablelistadapter extends baseexpandablelistadapter {

 private context mcontext;
 
 //父列表数据
 private string[] groups ={"group1","group2","group3","group4",""};
 
 //子列表数据
 private string [][] children ={
 {"child1"},
 {"child1","child2"},
 {"child1","child2","child3"},
 {"child1","child2","child3","child4"},
 };
 
 myexpandablelistadapter(context context){
 mcontext = context;
 }
 @override
 public object getchild(int groupposition, int childposition) {
 // todo auto-generated method stub
 return children[groupposition][childposition];
 }

 @override
 public long getchildid(int groupposition, int childposition) {
 // todo auto-generated method stub
 return childposition;
 }

 //取子列表中的某一项的view
 @override
 public view getchildview(int groupposition, int childposition,
 boolean islastchild, view convertview, viewgroup parent) {
 textview textview = getgenericview();;
 textview.settext(getchild(groupposition, childposition).tostring());
 return textview;
 }

 @override
 public int getchildrencount(int groupposition) {
 // todo auto-generated method stub
 return children[groupposition].length;
 }

 @override
 public object getgroup(int groupposition) {
 return groups[groupposition];
 }

 @override
 public int getgroupcount() {
 // todo auto-generated method stub
 return groups.length;
 }

 @override
 public long getgroupid(int groupposition) {
 // todo auto-generated method stub
 return groupposition;
 }

 @override
 public view getgroupview(int groupposition, boolean isexpanded,
 view convertview, viewgroup parent) {
 textview textview = getgenericview();
 textview.settext(getgroup(groupposition).tostring());
 
 return textview;
 }

 @override
 public boolean hasstableids() {
 // todo auto-generated method stub
 return true;
 }

 @override
 public boolean ischildselectable(int groupposition, int childposition) {
 // todo auto-generated method stub
 return true;
 }

 //获取某一项的view的逻辑
 private textview getgenericview(){
 abslistview.layoutparams lp = new abslistview.layoutparams(viewgroup.layoutparams.fill_parent,48);
 textview textview = new textview(mcontext);
 textview.setlayoutparams(lp);
 textview.setgravity(gravity.center_vertical | gravity.left);
 textview.setpadding(32, 0, 0, 0);
 return textview;
 }
 
}

 运行的结果如下：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。