实例教程八：采用ListView实现数据列表显示

不错的帖子：

分享一个Android火焰效果程序
http://www.eoeandroid.com/thread-210395-1-1.html

android 查询工具源代码
http://www.eoeandroid.com/thread-210365-1-1.html

Android在线音乐播放器
http://www.eoeandroid.com/thread-210352-1-1.html

-------------------正文--------------------------

原文链接：http://www.eoeandroid.com/thread-201372-1-1.html

继上一章的数据，继续添加内容
item.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="horizontal" >



    <TextView

        android:id="@+id/txtName"

        android:layout_width="120dp"

        android:layout_height="wrap_content"

        android:text="xxxxx" />



    <TextView

        android:id="@+id/txtPhone"

        android:layout_width="150dp"

        android:layout_height="wrap_content"

        android:text="xxxxx" />



    <TextView

        android:id="@+id/txtAmount"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="2000" />



</LinearLayout>

main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical" >

    

    <LinearLayout 

        android:layout_width="fill_parent"

    android:layout_height="wrap_content"

    android:orientation="horizontal">

        

        <TextView 

            android:layout_width="120dp"

            android:layout_height="wrap_content"

            android:text="@string/name"/>

        

        <TextView 

            android:layout_width="120dp"

            android:layout_height="wrap_content"

            android:text="@string/phone"/>

        

        <TextView 

            android:layout_width="fill_parent"

            android:layout_height="wrap_content"

            android:text="@string/amount"/>

        

    </LinearLayout>



    <ListView

        android:layout_width="fill_parent"

        android:layout_height="fill_parent"

        android:id="@+id/lstShow" />



</LinearLayout>

package cn.itcast.db;



import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;



import cn.itcast.domain.Person;

import cn.itcast.domain.PersonAdapter;

import cn.itcast.service.PersonService;

import android.app.Activity;

import android.database.Cursor;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.ListView;

import android.widget.SimpleAdapter;

import android.widget.SimpleCursorAdapter;

import android.widget.Toast;

import android.widget.AdapterView.OnItemClickListener;



public class MainActivity extends Activity {

        //在Android平台上，集成了一个嵌入式关系型数据库——SQLite

        //SQLite3支持NULL、INTEGER、REAL(浮点数字)、TEXT(字符串文本)和BLOB(二进制对象)数据类型

        //虽然它支持的类型只有5种，但实际上sqlite3也接受varchar(n)、char(n)、decimal(p, s)等数据

        //只不过在运行或保存时会转成对应的五种数据类型

        //SQLite最大的特点是你可以把各种类型的数据保存到任何字段中，而不用关心字段声明的数据类型是什么



        private ListView lstShow;

        private PersonService personService;



        @Override

        public void onCreate(Bundle savedInstanceState) {

                super.onCreate(savedInstanceState);

                setContentView(R.layout.main);



                personService = new PersonService(this);                

                lstShow = (ListView)this.findViewById(R.id.lstShow);

                lstShow.setOnItemClickListener(new ItemClickListener());

                //show();

                //show2();

                show3();

        }

        

        private final class ItemClickListener implements OnItemClickListener{

                @Override

                public void onItemClick(AdapterView<?> parent, View view, int position,

                                long id) {

                        

                        ListView lView = (ListView)parent;

                        //和show()3配对

                        Person person = (Person)lView.getItemAtPosition(position);

                        Toast.makeText(getApplicationContext(), person.getId().toString(), 1).show();

                        

                        //和show()2配对

                        Cursor cursor = (Cursor)lView.getItemAtPosition(position);

                        int personId = cursor.getInt(cursor.getColumnIndex("_id"));

                        Toast.makeText(getApplicationContext(), personId, 1).show();

                        

                        //和show()配对

                        List<HashMap<String, Object>> hashMap = (List<HashMap<String, Object>>)lView.getItemAtPosition(position);

                        int Id = Integer.valueOf(hashMap.get(personId).get("personId").toString());

                        Toast.makeText(getApplicationContext(), Id, 1).show();

                }                

        }



        //自定义适配器

        private void show3() {

                List<Person> persons = personService.getScrollData(0, 20);

                PersonAdapter adapter = new PersonAdapter(this, persons, R.layout.item);

                lstShow.setAdapter(adapter);

        }



        private void show2() {

                Cursor cursor = personService.getCursorScrollData(0, 20);

                SimpleCursorAdapter adapter = 

                        new SimpleCursorAdapter(this, R.layout.item, cursor,

                                        new String[]{"name", "phone", "amount"}, 

                                        new int[]{R.id.txtName, R.id.txtPhone, R.id.txtAmount});

                lstShow.setAdapter(adapter);

                

                //直接运行会报错，原因是SimpleCursorAdapter要求结果集中必须包含_id字段

                //修复方法：1.把数据库表中的主键名称personId改为_id

                //2.处理查询后的结果集

        }



        private void show() {

                List<Person> persons = personService.getScrollData(0, 20);

                List<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();

                for(Person person : persons){

                        HashMap<String, Object> item = new HashMap<String, Object>();

                        item.put("name", person.getName());

                        item.put("phone", person.getPhone());

                        item.put("amount", person.getAmount());

                        item.put("id", person.getId());

                        data.add(item);

                }

                SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item,

                                new String[]{"name", "phone", "amount"}, 

                                new int[]{R.id.txtName, R.id.txtPhone, R.id.txtAmount});

                lstShow.setAdapter(adapter);

                //listView内部操作过程

                //{

                //        int total = adapter.getCount(); //用于得到数据总数

                //        int perpage = 7;

                //        for (int i = 0; i < perpage; i++) {

                //                View view = adapter.getView(i, convertView, parent); //用于得到条目对应的View

                //                //显示条目

                //        }

                //}

        }



}

package cn.itcast.domain;



import java.util.List;



import cn.itcast.db.R;



import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.TextView;



public class PersonAdapter extends BaseAdapter {

        private List<Person> persons; //绑定数据

        private int resource; //绑定条目界面

        private LayoutInflater inflater;

        

        public PersonAdapter(Context context, List<Person> persons, int resouce){

                this.persons = persons;

                this.resource = resource;

                inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        }



        @Override

        public int getCount() {

                return persons.size(); //得到数据总数

        }



        @Override

        public Object getItem(int position) {

                return persons.get(position);

        }



        @Override

        public long getItemId(int position) {

                return position;

        }



        @Override

        public View getView(int position, View convertView, ViewGroup parent) {

                TextView txtName = null;

                TextView txtPhone = null;

                TextView txtAmount = null;

                //这样提升性能

                if(convertView == null){ //表明现在是第1页

                        inflater.inflate(resource, null); //生成条目界面对象

                        

                        txtName = (TextView)convertView.findViewById(R.id.txtName);

                        txtPhone = (TextView)convertView.findViewById(R.id.txtPhone);

                        txtAmount = (TextView)convertView.findViewById(R.id.txtAmount);

                        

                        ViewCache cache = new ViewCache();

                        cache.txtName = txtName;

                        cache.txtPhone = txtPhone;

                        cache.txtAmount = txtAmount;

                        

                        convertView.setTag(cache);

                }else{

                        ViewCache cache = (ViewCache)convertView.getTag();

                        txtName = cache.txtName;

                        txtPhone = cache.txtPhone;

                        txtAmount = cache.txtAmount;

                }

                                

                Person person = persons.get(position);

                //下面代码实现数据绑定

                txtName.setText(person.getName());

                txtPhone.setText(person.getPhone());

                txtAmount.setText(person.getAmount().toString());

                

                return null;

        }

        

        private final class ViewCache{

                public TextView txtName;

                public TextView txtPhone;

                public TextView txtAmount;

        }

}