ListView_BaseAdapter

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="名字"
android:textSize="25sp"
/>
<LinearLayout
android:layout_alignParentRight="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TextView
android:id="@+id/tv_phone"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="号码"
/>
<TextView
android:id="@+id/tv_salary"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="工资"
/>
</LinearLayout>
</RelativeLayout>

public class MainActivity extends Activity {

List<Person> personList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

personList = new ArrayList<Person>();
//把数据库的数据查询出来
MyOpenHelper oh = new MyOpenHelper(this);
SQLiteDatabase db = oh.getWritableDatabase();
Cursor cursor = db.query("person", null, null, null, null, null, null, null);
while(cursor.moveToNext()){
String _id = cursor.getString(0);
String name = cursor.getString(1);
String salary = cursor.getString(2);
String phone = cursor.getString(3);

Person p = new Person(_id, name, phone, salary);
personList.add(p);
}

ListView lv = (ListView) findViewById(R.id.lv);
lv.setAdapter(new MyAdapter());
}

class MyAdapter extends BaseAdapter{

//系统调用，用来获知集合中有多少条元素
@Override
public int getCount() {
return personList.size();
}

//由系统调用，获取一个View对象，作为ListView的条目
//position:本次getView方法调用所返回的View对象，在listView中是处于第几个条目，那么position的值就是多少
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Person p = personList.get(position);

// TextView tv = new TextView(MainActivity.this);
System.out.println("getView调用：" + position + ";" + convertView);
// tv.setText(p.toString());
// tv.setTextSize(18);

View v = null;
//判断条目是否有缓存
if(convertView == null){
//把布局文件填充成一个View对象
v = View.inflate(MainActivity.this, R.layout.item_listview, null);
}
else{
v = convertView;
}

//获取布局填充器对象
// LayoutInflater inflater = LayoutInflater.from(MainActivity.this);
// 使用布局填充器填充布局文件
// View v2 = inflater.inflate(R.layout.item_listview, null);

// LayoutInflater inflater2 = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
// View v3 = inflater2.inflate(R.layout.item_listview, null);

//通过资源id查找组件,注意调用的是View对象的findViewById
TextView tv_name = (TextView) v.findViewById(R.id.tv_name);
tv_name.setText(p.getName());
TextView tv_phone = (TextView) v.findViewById(R.id.tv_phone);
tv_phone.setText(p.getPhone());
TextView tv_salary = (TextView) v.findViewById(R.id.tv_salary);
tv_salary.setText(p.getSalary());
return v;
}

@Override
public Object getItem(int position) {
return null;
}

@Override
public long getItemId(int position) {
return 0;
}

}

}