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:
<?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>
my_listitem.xml布局文件:
<?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>
LsActivity类:
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);}}
运行结果如下图所示:
示例二:目录结构

main.xml布局文件:
<?xml version="1.0" encoding="utf-8"?><!-- 使用相对布局 --><RelativeLayoutxmlns: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>
实体JavaBean:
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;}}
自定义适配器PersonAdapter
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 */@Overridepublic int getCount() {return persons.size();}@Overridepublic Object getItem(int position) {return persons.get(position);}@Overridepublic 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? */@Overridepublic 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;}}
类LsActivity
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;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);initData();personAdapter =new PersonAdapter(LsActivity.this, R.layout.main, persons);setListAdapter(personAdapter);registerForContextMenu(getListView());}@Overrideprotected 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"));}}
运行结果

希望本文所述对大家的Android程序设计有所帮助。