本文实例讲述了android控件之listview用法。分享给大家供大家参考。具体如下：
示例一：
在android开发中listview是比较常用的组件，它以列表的形式展示具体内容，并且能够根据数据的长度自适应显示。
main.xml布局文件：
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<?xml version="1.0" encoding="utf-8"?>
<linearlayout android:id="@+id/linearlayout01"
android:layout_width="fill_parent" android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<listview android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/mylistview">
</listview>
</linearlayout>
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my_listitem.xml布局文件：
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<?xml version="1.0" encoding="utf-8"?>
<linearlayout android:layout_width="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_height="wrap_content"
android:id="@+id/mylistitem"
android:paddingbottom="3dip"
android:paddingleft="10dip">
<textview android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="@+id/itemtitle"
android:textsize="20dip">
</textview>
<textview android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="@+id/itemtext">
</textview>
</linearlayout>
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lsactivity类：
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package com.ljq.ls;
import java.util.arraylist;
import java.util.hashmap;
import java.util.list;
import android.app.activity;
import android.os.bundle;
import android.widget.listview;
import android.widget.simpleadapter;
public class lsactivity extends activity {
private listview list = null;
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.main);
list = (listview) findviewbyid(r.id.mylistview);
//组织数据源
list<hashmap<string, string>> mylist = new arraylist<hashmap<string, string>>();
for(int i=0;i<10;i++) {
hashmap<string, string> map = new hashmap<string, string>();
map.put("itemtitle", "this is title");
map.put("itemtext", "this is text");
mylist.add(map);
}
//配置适配器
simpleadapter adapter = new simpleadapter(this,
mylist,//数据源
r.layout.my_listitem,//显示布局
new string[] {"itemtitle", "itemtext"}, //数据源的属性字段
new int[] {r.id.itemtitle,r.id.itemtext}); //布局里的控件id
//添加并且显示
list.setadapter(adapter);
}
}
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运行结果如下图所示：
示例二：
目录结构
main.xml布局文件：
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<?xml version="1.0" encoding="utf-8"?>
<!-- 使用相对布局 -->
<relativelayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<textview android:layout_width="100dip"
android:layout_height="wrap_content"
android:layout_marginleft="30dip"
android:textsize="20dip"
android:id="@+id/id"/>
<textview android:layout_width="100dip"
android:layout_height="wrap_content"
android:layout_aligntop="@id/id"
android:layout_torightof="@id/id"
android:textsize="20dip"
android:id="@+id/name"/>
<textview android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_aligntop="@id/name"
android:layout_torightof="@id/name"
android:textsize="20dip"
android:id="@+id/age"/>
</relativelayout>
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实体javabean：
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package com.ljq.domain;
public class person {
private string id;
private string name;
private string age;
public person() {
super();
}
public person(string id, string name, string age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public string getid() {
return id;
}
public void setid(string id) {
this.id = id;
}
public string getname() {
return name;
}
public void setname(string name) {
this.name = name;
}
public string getage() {
return age;
}
public void setage(string age) {
this.age = age;
}
}
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自定义适配器personadapter
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package com.ljq.ls;
import java.util.list;
import com.ljq.domain.person;
import android.content.context;
import android.view.layoutinflater;
import android.view.view;
import android.view.viewgroup;
import android.widget.arrayadapter;
import android.widget.textview;
/**
* listview加载adapter的过程
*
* 1、先判断adapter有多少数据项，根据这个数据确定有多少个item
*
* 2、确定每个item里加载哪个view
*
* 3、在view里加载要显示的数据
*
* @author jiqinlin
*
*/
public class personadapter extends arrayadapter{
private layoutinflater layoutinflater = null;
private list<person> persons;
public personadapter(context context, int textviewresourceid, list objects) {
super(context, textviewresourceid, objects);
layoutinflater = layoutinflater.from(context);
persons = objects;
}
/**
* 获取adapter里有多少个数据项
*/
@override
public int getcount() {
return persons.size();
}
@override
public object getitem(int position) {
return persons.get(position);
}
@override
public long getitemid(int position) {
return position;
}
/**
* 创建显示的数据界面
*
* adapter的作用就是listview界面与数据之间的桥梁，
* 当列表里的每一项显示到页面时，都会调用adapter的getview方法返回一个view。
* 想过没有？ 在我们的列表有1000000项时会是什么样的？是不是会占用极大的系统资源？
*/
@override
public view getview(int position, view convertview, viewgroup parent) {
/*
// 优化前
viewholder holder = new viewholder();
convertview = layoutinflater.inflate(r.layout.main, null);
holder.id = (textview)convertview.findviewbyid(r.id.id);
holder.name = (textview)convertview.findviewbyid(r.id.name);
holder.age = (textview)convertview.findviewbyid(r.id.age);
convertview.settag(holder);
holder.id.settext(persons.get(position).getid());
holder.name.settext(persons.get(position).getname());
holder.age.settext(persons.get(position).getage());
return convertview;
*/
// 优化后
viewholder holder;
if(convertview == null){
convertview = layoutinflater.inflate(r.layout.main, null);
holder = new viewholder();
holder.id = (textview)convertview.findviewbyid(r.id.id);
holder.name = (textview)convertview.findviewbyid(r.id.name);
holder.age = (textview)convertview.findviewbyid(r.id.age);
convertview.settag(holder);
}else{
holder = (viewholder)convertview.gettag();
}
holder.id.settext(persons.get(position).getid());
holder.name.settext(persons.get(position).getname());
holder.age.settext(persons.get(position).getage());
return convertview;
}
/**
* 界面上的显示控件
*
* @author jiqinlin
*
*/
private static class viewholder{
private textview id;
private textview name;
private textview age;
}
}
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类lsactivity
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package com.ljq.ls;
import java.util.arraylist;
import android.app.listactivity;
import android.os.bundle;
import android.view.view;
import android.widget.listview;
import android.widget.toast;
import com.ljq.domain.person;
public class lsactivity extends listactivity {
private arraylist<person> persons = new arraylist<person>();
private personadapter personadapter = null;
@override
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
initdata();
personadapter =new personadapter(lsactivity.this, r.layout.main, persons);
setlistadapter(personadapter);
registerforcontextmenu(getlistview());
}
@override
protected void onlistitemclick(listview l, view v, int position, long id) {
super.onlistitemclick(l, v, position, id);
person person = persons.get(position);
toast.maketext(lsactivity.this, person.getid()+":"+person.getname()
+":"+person.getage(), toast.length_long).show();
return;
}
private void initdata(){
persons.add(new person("序号", "姓名", "年龄"));
persons.add(new person("1", "ljq1", "20"));
persons.add(new person("2", "ljq2", "20"));
persons.add(new person("3", "ljq3", "20"));
persons.add(new person("4", "ljq4", "20"));
persons.add(new person("5", "ljq5", "20"));
persons.add(new person("6", "ljq6", "20"));
persons.add(new person("7", "ljq7", "20"));
persons.add(new person("8", "ljq8", "20"));
persons.add(new person("9", "ljq9", "20"));
}
}
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运行结果
希望本文所述对大家的android程序设计有所帮助。