Android（三）数据存储之三SQLite嵌入式数据库 3

hongmeigui22027

在mail.xml所在目录里添加一个contactitem.xml：

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"          android:layout_width="wrap_content" android:layout_height="wrap_content">            <!-- contact.id -->          <TextView android:layout_width="30dip" android:layout_height="wrap_content"                    android:textSize="20sp" android:id="@+id/tv_id" />            <!-- contact.name -->          <TextView android:layout_width="150dip" android:layout_height="wrap_content"                    android:textSize="20sp" android:layout_toRightOf="@id/tv_id"                    android:layout_alignTop="@id/tv_id" android:id="@+id/tv_name" />            <!-- contact.phone -->          <TextView android:layout_width="150dip" android:layout_height="wrap_content"                    android:textSize="20sp" android:layout_toRightOf="@id/tv_name"                    android:layout_alignTop="@id/tv_name" android:id="@+id/tv_phone" />   </RelativeLayout>

 
 
       编辑AndroidSQLite类：

package com.changcheng.sqlite;   import java.util.ArrayList; import java.util.HashMap; import java.util.List; import com.changcheng.sqlite.R; import com.changcheng.sqlite.entity.Contact; import com.changcheng.sqlite.service.ContactsService; 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.Toast; import android.widget.AdapterView.OnItemClickListener;   public class AndroidSQLite extends Activity {          /** Called when the activity is first created. */          @Override          public void onCreate(Bundle savedInstanceState) {                    super.onCreate(savedInstanceState);                    setContentView(R.layout.main);                    // 获取分页数据                    ContactsService contactsService = new ContactsService(this);                    List<Contact> contacts = contactsService.getScrollData(0, 3);                    // 获取ListView                    ListView lv = (ListView) this.findViewById(R.id.listView);                    // 生成List<? extends Map<String, ?>>数据                    List<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();                    for (Contact contact : contacts) {                             HashMap<String, Object> item = new HashMap<String, Object>();                             item.put("_id", contact.get_id());                             item.put("name", contact.getName());                             item.put("phone", contact.getPhone());                             data.add(item);                    }                    // 生成Adapter                    SimpleAdapter adapter = new SimpleAdapter(this, data,                                      R.layout.contactitem, new String[] { "_id", "name", "phone" },                                      new int[] { R.id.tv_id, R.id.tv_name, R.id.tv_phone });                    // 设置ListView适配器                    lv.setAdapter(adapter);                                       // 为ListView添加事件                    lv.setOnItemClickListener(new OnItemClickListener() {                               @Override                             public void onItemClick(AdapterView<?> parent, View view,                                                int position, long id) {                                      HashMap<String, Object> item = (HashMap<String, Object>) parent                                                         .getItemAtPosition((int) id);                                      Toast.makeText(AndroidSQLite.this, item.get("name").toString(),                                                         1).show();                             }                      });          } }

 
上面编写的分页显示数据比较麻烦，Android为我们提供了一个SimpleCursorAdapter类。使用它可以方便的显示分页数据。将AndroidSQLite类修改为：
      

package com.changcheng.sqlite;   import com.changcheng.sqlite.R; import com.changcheng.sqlite.service.ContactsService; import android.app.Activity; import android.database.Cursor; import android.os.Bundle; import android.widget.ListView; import android.widget.SimpleCursorAdapter;   public class AndroidSQLite extends Activity {          /** Called when the activity is first created. */          @Override          public void onCreate(Bundle savedInstanceState) {                    super.onCreate(savedInstanceState);                    setContentView(R.layout.main);                      // 获取分页数据                    ContactsService contactsService = new ContactsService(this);                    Cursor cursor = contactsService.getScrollDataCursor(0, 3);                    // 获取ListView                    ListView lv = (ListView) this.findViewById(R.id.listView);                    // 创建Adapter                    SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,                                      R.layout.contactitem, cursor, new String[] { "_id", "name",                                                         "phone" }, new int[] { R.id.tv_id, R.id.tv_name,                                                         R.id.tv_phone });                    // 设置ListView适配器                    lv.setAdapter(adapter);                      // 为ListView添加事件                    lv.setOnItemClickListener(new OnItemClickListener() {                               @Override                             public void onItemClick(AdapterView<?> parent, View view,                                                int position, long id) {                                      Cursor cursor = (Cursor) parent                                                         .getItemAtPosition((int) position);                                      Toast.makeText(AndroidSQLite.this, cursor.getString(1), 1)                                                         .show();                             }                    });          } }

 
       OK，在Android中的SQLite操作总结结束！