Android（3）数据存储之三SQLite嵌入式数据库 3

Android（三）数据存储之三SQLite嵌入式数据库 3

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">

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???????? <!-- contact.id -->

???????? <TextView android:layout_width="30dip" android:layout_height="wrap_content"

?????????????????? android:textSize="20sp" android:id="@+id/tv_id" />

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???????? <!-- 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" />

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???????? <!-- 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" />

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</RelativeLayout>

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?????? 编辑AndroidSQLite类：

package com.changcheng.sqlite;

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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;

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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() {

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??????????????????????????? @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();

??????????????????????????? }

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?????????????????? });

???????? }

}

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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;

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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);

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?????????????????? // 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);

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?????????????????? // 为ListView添加事件

?????????????????? lv.setOnItemClickListener(new OnItemClickListener() {

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??????????????????????????? @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();

??????????????????????????? }

?????????????????? });

???????? }

}

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?????? OK，在Android中的SQLite操作总结结束！