ListView实现数据列表显示

要将数据库中的数据列表显示在屏幕上，我们要使用ListView这个控件，当用户从数据库中取出数据时，要将数据绑定到显示控件上，如何绑定呢，我们需要创建适配器进行绑定，创建适配器有两种方式：

第一种是用SimpleAdapter创建（要求绑定的数据是List<HashMap<String, Object>>数据类型）

第二种是用SimpleCursorAdapter创建（要求绑定的数据是Cursor数据类型）

显示效果如图所示：

界面布局:

item.xml

<?xml version="1.0" encoding="utf-8"?>
<!--item -->
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="horizontal"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">
  <!-- 名称 -->
  <TextView
   android:layout_width="130dp"
   android:layout_height="wrap_content"
   android:id="@+id/name"
  />
  <!-- 电话 -->
  <TextView
   android:layout_width="150dp"
   android:layout_height="wrap_content"
   android:id="@+id/phone"
  />
  <!-- 存款 -->
  <TextView
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:id="@+id/amount"
  />
</LinearLayout>

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
 <!-- 标题 -->
 <LinearLayout
  android:orientation="horizontal"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content">

  <TextView
   android:layout_width="130dp"
   android:layout_height="wrap_content"
   android:text="姓名"
  />

   <TextView
   android:layout_width="150dp"
   android:layout_height="wrap_content"
   android:text="电话"
  />

  <TextView
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="存款"
  />

</LinearLayout>
 <!-- ListView控件 -->
<ListView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/listView"
    />
</LinearLayout>

 使用SimpleAdapter进行数据绑定

public class MainActivity extends Activity {
    private PersonService service;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        service = new PersonService(this);
        ListView listView = (ListView) this.findViewById(R.id.listView);

        //获取到集合数据
        List<Person> persons = service.getScrollData(0, 10);
        List<HashMap<String, Object>> data = new ArrayList<HashMap<String,Object>>();
        for(Person person : persons){
            HashMap<String, Object> item = new HashMap<String, Object>();
            item.put("id", person.getId());
            item.put("name", person.getName());
            item.put("phone", person.getPhone());
            item.put("amount", person.getAmount());
            data.add(item);
        }
       //创建SimpleAdapter适配器将数据绑定到item显示控件上
       SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item,
                new String[]{"name", "phone", "amount"}, new int[]{R.id.name, R.id.phone, R.id.amount});
       //实现列表的显示
       listView.setAdapter(adapter);
       //条目点击事件
       listView.setOnItemClickListener(new ItemClickListener());
    }
       //获取点击事件
    private final class ItemClickListener implements OnItemClickListener{

        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            ListView listView = (ListView) parent;
            HashMap<String, Object> data = (HashMap<String, Object>) listView.getItemAtPosition(position);
            String personid = data.get("id").toString();
            Toast.makeText(getApplicationContext(), personid, 1).show();
        }
    }
}

 使用SimpleCursorAdapter进行数据绑定

public class MainActivity extends Activity {
    private PersonService service;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        service = new PersonService(this);
        ListView listView = (ListView) this.findViewById(R.id.listView);
        //获取游标
        Cursor cursor = service.getCursorScrollData(0, 10);
        //创建SimpleCursorAdapter适配器将数据绑定到item显示控件上
        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.item, cursor,
                new String[]{"name", "phone", "amount"}, new int[]{R.id.name, R.id.phone, R.id.amount});
        listView.setAdapter(adapter);
        //条目点击事件
        listView.setOnItemClickListener(new ItemClickListener());
    }

    private final class ItemClickListener implements OnItemClickListener{

        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            ListView listView = (ListView) parent;
            Cursor cursor = (Cursor) listView.getItemAtPosition(position);
            String personid = String.valueOf(cursor.getInt(cursor.getColumnIndex("_id")));
            Toast.makeText(getApplicationContext(), personid, 1).show();
        }
    }
}

注意：使用第二种方式在获取数据集合时必须指定主键"_id"