android中滑动SQLite数据库分页加载

今天用到了android中滑动SQlit数据库分页加载技术，写了个测试工程，将代码贴出来和大家交流一下：

MainActivity

package com.example.testscrollsqlite;import java.util.ArrayList;import android.app.ActionBar.LayoutParams;import android.app.Activity;import android.os.Bundle;import android.view.Gravity;import android.view.Menu;import android.view.View;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.AbsListView.OnScrollListener;import android.widget.Adapter;import android.widget.BaseAdapter;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.TextView;public class MainActivity extends Activity implements OnScrollListener{private TextView loadInfo;private ListView listView;private LinearLayout loadLayout;private ArrayList<String> items;private DatabaseService service;private int currentPage = 1; //默认在第一页private static final int lineSize = 7;    //每次显示数 private int allRecorders = 0;  //全部记录数private int pageSize = 1;  //默认共一页private int lastItem;private Aleph0 baseAdapter;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);listView = (ListView) findViewById(R.id.listview);//创建一个角标线性布局用来显示"正在加载"loadLayout = new LinearLayout(this);loadLayout.setGravity(Gravity.CENTER);//定义一个文本显示“正在加载”loadInfo = new TextView(this);loadInfo.setText("正在加载...");loadInfo.setGravity(Gravity.CENTER);//增加组件 loadLayout.addView(loadInfo, new LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));//增加到listView底部listView.addFooterView(loadLayout);listView.setOnScrollListener(this);showAllData();}/** * 读取全部数据 */public void showAllData(){service = new DatabaseService(this);allRecorders = service.getCount();//计算总页数pageSize = (allRecorders + lineSize -1) / lineSize;  System.out.println("allRecorders =  " + allRecorders);System.out.println("pageSize  =  " + pageSize);items = service.getAllItems(currentPage, lineSize);for(int i=0; i<items.size(); i++){System.out.println(items.get(i));}baseAdapter = new Aleph0();listView.setAdapter(baseAdapter);}@Overridepublic void onScroll(AbsListView view, int firstVisible, int visibleCount,int totalCount) {lastItem = firstVisible + visibleCount - 1; //统计是否到最后}@Overridepublic void onScrollStateChanged(AbsListView view, int scorllState) {System.out.println("进入滚动界面了");//是否到最底部并且数据没读完if(lastItem == baseAdapter.getCount() && currentPage < pageSize    //不再滚动&& scorllState == OnScrollListener.SCROLL_STATE_IDLE){currentPage ++;//设置显示位置listView.setSelection(lastItem);//增加数据appendDate();}}/** * 增加数据 */private void appendDate(){ArrayList<String> additems = service.getAllItems(currentPage, lineSize);baseAdapter.setCount(baseAdapter.getCount() + additems.size());//判断，如果到了最末尾则去掉“正在加载”if(allRecorders == baseAdapter.getCount()){listView.removeFooterView(loadLayout);}items.addAll(additems);//通知记录改变baseAdapter.notifyDataSetChanged();}class Aleph0 extends BaseAdapter {int count = lineSize; /* starting amount */public int getCount() {return count;} public void setCount(int count){this.count = count;}public Object getItem(int pos) {return pos;}public long getItemId(int pos) {return pos;}public View getView(int pos, View v, ViewGroup p) {TextView view = new TextView(MainActivity.this);view.setTextSize(60);if(items != null){view.setText(items.get(pos));}else{view.setText(pos);}return view;}}}

MyDBOpenHelper

package com.example.testscrollsqlite;import android.content.ContentValues;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.provider.BaseColumns;public class MyDBOpenHelper extends SQLiteOpenHelper {private static final String DATABASE_NAME = "merit.db";private static final int DATABASE_VERSION = 1;private static final String TABLE_NAME = "database";public static final String FIELD_TITLE = "title";/** *  * @param context *            上下文 * @param name *            数据库的名字 * @param factory *            结果集游标工厂(一般使用默认) * @param version *            数据库的版本号（必须version>=1） */public MyDBOpenHelper(Context context) {super(context, DATABASE_NAME, null, DATABASE_VERSION);}/** * 在MyDBOpenHelper第一次new出来时，系统会调用onCreate方法 */@Overridepublic void onCreate(SQLiteDatabase db) {System.out.println("我被调用了");String sql = "Create table " + TABLE_NAME + "(" + BaseColumns._ID+ " integer primary key autoincrement," + FIELD_TITLE+ " text )";db.execSQL(sql);initDatabase(db);}// 向数据库的表中插入一些数据。private void initDatabase(SQLiteDatabase db) {ContentValues cv = new ContentValues();cv.put("title", "cctv1 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv2 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv3 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv4 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv5 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv6 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv7 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv8 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv9 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("title", "cctv10 news");db.insert(TABLE_NAME, null, cv);cv.clear();cv.put("news_title", "guangshui tv");db.insert(TABLE_NAME, null, cv);}@Overridepublic void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {// TODO Auto-generated method stub}}

DatabaseService

package com.example.testscrollsqlite;import java.util.ArrayList;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;public class DatabaseService { private Context mContext;private MyDBOpenHelper dbHelper;public DatabaseService(Context context) {// TODO Auto-generated constructor stubmContext = context;dbHelper = new MyDBOpenHelper(mContext);}// 添加public void insert(String title) {SQLiteDatabase db = dbHelper.getWritableDatabase();String sql = "insert into database(title) values(?)";db.execSQL(sql, new String[] { title });}// 删除public void delete(String title) {SQLiteDatabase db = dbHelper.getWritableDatabase();String sql = "delete from database where title = ?";db.execSQL(sql, new String[] { title });}// 查找public ArrayList<String> find(int id) {SQLiteDatabase db = dbHelper.getWritableDatabase();String sql = "select * from database where _id = ? ";Cursor c = db.rawQuery(sql, new String[] { String.valueOf(id) });ArrayList<String> titles = new ArrayList<String>();if (c.moveToNext()) {String title = c.getString(c.getColumnIndexOrThrow(MyDBOpenHelper.FIELD_TITLE));titles.add(title);return titles;}// 不用忘记关闭Cursor。c.close();return null;}// 更新public void upDate(int id, String title) {SQLiteDatabase db = dbHelper.getWritableDatabase();String sql = "update database set title =? where _id = ?";db.execSQL(sql,new String[] { String.valueOf(title), String.valueOf(id) });}// 查询记录的总数public int getCount() {SQLiteDatabase db = dbHelper.getWritableDatabase();String sql = "select count(*) from database";Cursor c = db.rawQuery(sql, null);c.moveToFirst();int length = c.getInt(0);c.close();return length;}/** * 分页查询 *  * @param currentPage 当前页 * @param pageSize 每页显示的记录 * @return 当前页的记录 */public ArrayList<String> getAllItems(int currentPage, int pageSize) {int firstResult = (currentPage - 1) * pageSize;int maxResult = currentPage * pageSize;SQLiteDatabase db = dbHelper.getWritableDatabase();String sql = "select * from database limit ?,?";Cursor mCursor = db.rawQuery(sql,new String[] { String.valueOf(firstResult),String.valueOf(maxResult) });ArrayList<String> items = new ArrayList<String>();int columnCount  = mCursor.getColumnCount();while (mCursor.moveToNext()) {String item = mCursor.getString(mCursor.getColumnIndexOrThrow(MyDBOpenHelper.FIELD_TITLE));items.add(item);}//不要关闭数据库return items;}}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"        android:orientation="vertical" >    <ListView         android:layout_width="match_parent"        android:layout_height="wrap_content"        android:id="@+id/listview">            </ListView></LinearLayout>

源代码下载http://download.csdn.net/detail/lxq_xsyu/5955673

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