simpleAdaper 用的list<Map> 比较麻烦
array在只显示一行信息的listview中有用
cursoradapter用于数据库cursor的显示
package cn.itcast.db;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import cn.itcast.db.dao.PersonDBDao;
import cn.itcast.db.domain.Person;
import android.app.Activity;
import android.database.Cursor;
import android.database.DataSetObserver;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import android.widget.Toast;public class DbActivity extends Activity {private ListView mListView;private List<Person> persons;private LayoutInflater inflater; // 打气筒 ,充气泵@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);// inflater 是系统的一个服务 初始化服务inflater = (LayoutInflater) this.getSystemService(LAYOUT_INFLATER_SERVICE);setContentView(R.layout.main);// 第一步得到 组件的id的引用mListView = (ListView) this.findViewById(R.id.lv_all_person);PersonDBDao dao = new PersonDBDao(this);persons = dao.findAll();// 第二步 设置组件要显示的内容// listview 显示的东西 比较复杂,需要数据的适配器// mListView.setAdapter(new MyAdatper());List<Map<String, String>> data = new ArrayList<Map<String, String>>();for (Person person : persons) {HashMap<String, String> map = new HashMap<String, String>();map.put("name", person.getName());map.put("age", person.getAge() + "");data.add(map);}String [] personarr = new String[persons.size()];for(int i=0;i<persons.size();i++){personarr[i]= persons.get(i).getName();}/* mListView.setAdapter(new SimpleAdapter(DbActivity.this, data, R.layout.item,new String[]{"name","age"}, new int[]{R.id.tv_name,R.id.tv_age}));*/// mListView.setAdapter(new ArrayAdapter<String>(DbActivity.this, R.layout.item, R.id.tv_name, personarr));Cursor c = dao.findAllbyCursor();mListView.setAdapter(new SimpleCursorAdapter(this, R.layout.item, c,new String[] { "name", "age" }, new int[] { R.id.tv_name,R.id.tv_age }));mListView.setOnItemClickListener(new OnItemClickListener() {/*** parent 代表的是当前的listview view 代表的当前被点击条目对应的view对象 position* 当前条目在listview中的位置 id 行号 一般与position 相同的*/public void onItemClick(AdapterView<?> parent, View view,int position, long id) {/** 方法1 TextView tv_name = (TextView)* view.findViewById(R.id.tv_name); String name =* tv_name.getText().toString(); Toast.makeText(DbActivity.this,* name, Toast.LENGTH_LONG).show();*//** 方法2 String name = persons.get(position).getName();* Toast.makeText(DbActivity.this, name,* Toast.LENGTH_LONG).show();*/Person object = (Person) parent.getItemAtPosition(position);String name = object.getName();Toast.makeText(DbActivity.this, name, Toast.LENGTH_LONG).show();}});}// BaseAdapter 是 google的工程师 给ListAdapter的默认实现public class MyAdatper extends BaseAdapter {/*** 返回当前listview有多少个条目*/public int getCount() {return persons.size();}/*** 返回当前position位置对应的条目 的object对象*/public Object getItem(int position) {return persons.get(position);}/*** 返回当前position位置 某个条目的id*/public long getItemId(int position) {return position;}/*** 返回每一个条目显示的具体内容* * 计算当前界面 会有多少个条目出现 1.得到每一个textview的高度 2.得到listview的高度 3. listview高度/* textview高度 = 得到了一个屏幕显示的textview的个数* * listview的每一个条目的显示 都需要调用一次getview的方法 屏幕上有多个item显示 就会调用多少getview的方法* parent 代表的是 当前的这个listview*/public View getView(int position, View convertView, ViewGroup parent) {/** TextView tv = new TextView(DbActivity.this);* //tv.setText("我是第"+position+"个文本"); Person person =* persons.get(position); tv.setText(person.getName() +" | "+* person.getAge() ); System.out.println("我被调用了 "+ position); return* tv;*/View view = inflater.inflate(R.layout.item, null);Person person = persons.get(position);TextView tv_age = (TextView) view.findViewById(R.id.tv_age);TextView tv_name = (TextView) view.findViewById(R.id.tv_name);tv_age.setText("年龄为 " + person.getAge());tv_name.setText("姓名:" + person.getName());System.out.println("我被调用了 " + position);return view;}}
}