在模拟器里还能运行,但是多次滚动后就会卡住。放在手机上就闪退。望高手给出指引。
这是MainActivity里的代码
package com.itheima.db;
import java.util.List;
import org.w3c.dom.Text;
import com.itheima.db.dao.PersonDao;
import com.itheima.db.domain.Person;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends Activity {
private ListView lv;
private List persons;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
PersonDao dao = new PersonDao(this);
persons = dao.findAll();
lv = (ListView) findViewById(R.id.lv);
lv.setAdapter(new MyAdapter());
}
//默认实现类 simpleXX defaultXX baseXX
private class MyAdapter extends BaseAdapter{
/*
* 控制listview里面总共的条目
* */
@Override
public int getCount() {
return persons.size();//条目个数 == 集合的size
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView tv = new TextView(getApplicationContext());
tv.setTextSize(20);
tv.setTextColor(Color.BLACK);
//得到某个位置对应的person对象
Person person = persons.get(position);
tv.setText(person.toString());
return tv;
}
}
}
这是activity里面的代码
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/ll_root"
tools:context=".MainActivity" >
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>