Sqlite 数据库分页查询(ListView分页显示数据)

package com.example.sqlitepagetest;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

import android.database.Cursor;
import android.util.Log;

/**
 * <p>
 * </p>
 * 下午9:12:42
 * 
 * @auther dalvikCoder
 */
public class cls_city {

  public String _id = "";
  public String province = "";
  public String name = "";

  /**
   * 
   * select _id,province ,name from city order by _id limit perItemNum Offset
   * currentPage*perItemNum ;--currentPage 从零开始
   * <p>
   * 根据条目数量查询
   * </p>
   * 
   * @param dbh
   * @param num
   *            num[1]-->每一页显示的条目数量 num[0]--->从第几条开始
   * @return List<cls_city>
   */
  public static List<cls_city> getCityList(DatabaseHelper dbh, int num[]) {

    String sql = "select _id,province ,name from city order by _id limit "
        + num[0] + "," + num[1];

    Log.e("select city‘s sql --------------", sql);
    Cursor cursor = dbh.rawQuery(sql);
    List<cls_city> list = new ArrayList<cls_city>();
    cls_city cls = null;
    while (cursor.moveToNext()) {

      cls = new cls_city();
      setClassValueBycursor(cls, cursor);
      list.add(cls);
    }

    return list;
  }

  /**
   * <p>
   * 利用反射机制给对象赋值
   * </p>
   * @param obj
   * @param cursor void
   */
  public static void setClassValueBycursor(Object obj, Cursor cursor) {
    int ColCount = cursor.getColumnCount();
    int i = 0;
    for (i = 0; i < ColCount; i++) {
      String ColName = cursor.getColumnName(i);

      try {
        Field f = obj.getClass().getField(ColName);
        String ret = cursor.getString(i);
        if (f == null)
          continue;
        if (ret == null)
          ret = "";
        f.set(obj, ret);
      } catch (SecurityException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      } catch (NoSuchFieldException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      } catch (IllegalAccessException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
  }
}

package com.example.sqlitepagetest;

import android.util.SparseArray;
import android.view.View;

/**
 * <p>
 * ListView缓存的写法比较多种，下面也是其中一中，
 * </p>
 * 下午9:45:29
 * 
 * @auther dalvikCoder
 */
public class ViewHolder {
  // I added a generic return type to reduce the casting noise in client code
  @SuppressWarnings("unchecked")
  public static <T extends View> T get(View view, int id) {
    SparseArray<View> viewHolder = (SparseArray<View>) view.getTag();
    if (viewHolder == null) {
      viewHolder = new SparseArray<View>();
      view.setTag(viewHolder);
    }
    View childView = viewHolder.get(id);
    if (childView == null) {
      childView = view.findViewById(id);
      viewHolder.put(id, childView);
    }
    return (T) childView;
  }

}

 @Override
  public View getView(int position, View convertView, ViewGroup parent) {

    if (convertView == null) {

      convertView = inflater.inflate(R.layout.city_lv_item, null);

    }

    TextView cityId = ViewHolder.get(convertView, R.id.cityidtxt);
    TextView provincetxt = ViewHolder.get(convertView, R.id.provincetxt);
    TextView cityName = ViewHolder.get(convertView, R.id.nametxt);

    cls_city city = cityList.get(position);
    cityId.setText(city._id);
    provincetxt.setText(city.province);
    cityName.setText(city.name);

    return convertView;
  }

package com.example.sqlitepagetest;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;

public class MainActivity extends Activity {

  private ListView cityListView;
  private List<cls_city> cityList;
  private CityAdapter cityAdapter;

  private MyThread thread = null;

  /**
   * 每页有数据条数 这个数量可以根据需要更改，而不需在程序中更改具体数值
   * **/
  private int perPageItemNum = 100;
  /** 当前是第几页 0表示第一页 **/
  private int currentPage = 0;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    setUpView();

  }

  private void setUpView() {

    cityList = new ArrayList<cls_city>();

    try {
      Common.loadCityDatabase(this);
    } catch (Exception e) {
      e.printStackTrace();
    }
    Common.dbh = new DatabaseHelper(this, "city");
    cityListView = (ListView) findViewById(R.id.citylistview);

    cityAdapter = new CityAdapter(this, cityList);
    cityListView.setAdapter(cityAdapter);
    cityListView.setOnScrollListener(new OnScrollListener() {

      @Override
      public void onScrollStateChanged(AbsListView view, int scrollState) {

        if (view.getLastVisiblePosition() == view.getCount() - 1
            && scrollState == OnScrollListener.SCROLL_STATE_IDLE) {

          if (thread != null && !thread.isInterrupted()) {

            thread.interrupt();
            thread = null;
          }
          currentPage++;
          cityListView.setSelection(view.getLastVisiblePosition());// 设置显示位置，这句只是让Listview停留在最后末尾的显示而已，加不加影响不大
          thread = new MyThread();
          thread.start();

        }
      }

      @Override
      public void onScroll(AbsListView view, int firstVisibleItem,
          int visibleItemCount, int totalItemCount) {

      }
    });

    if (thread == null) {

      thread = new MyThread();
      thread.start();
    }
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }

  class MyThread extends Thread {

    @Override
    public void run() {

      int num[] = new int[2];
      num[0] = currentPage * perPageItemNum;// 0*50 1*50 2*50
      num[1] = perPageItemNum;
      List<cls_city> dataList = cls_city.getCityList(Common.dbh, num);
      // try {
      // Thread.sleep(1000);
      // } catch (InterruptedException e) {
      // e.printStackTrace();
      // }
      Message msg = new Message();
      msg.what = 1;
      msg.obj = dataList;
      mHandler.sendMessage(msg);

    }
  }

  private Handler mHandler = new Handler() {

    @Override
    public void handleMessage(Message msg) {

      super.handleMessage(msg);

      List<cls_city> dataList = (List<cls_city>) msg.obj;

      if (!dataList.isEmpty()) {

        cityAdapter.refresh(dataList);
      }
    }

  };

}

package com.example.sqlitepagetest;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;

import android.content.Context;

/**
 * <p>
 * </p>
 * 下午9:02:19
 * 
 * @auther dalvikCoder
 */
public class Common {

  public static DatabaseHelper dbh = null;

  public static void loadCityDatabase(Context context) throws Exception {

    // ------------创建路径
    String path = "/data/data/" + context.getPackageName() + "/databases";
    File file = new File(path);

    if (!file.exists()) {

      file.mkdirs();
    }
    // --------------该路径下创建数据库文件
    File f = new File(path, "city");
    if (!f.exists()) {

      InputStream is = context.getResources().openRawResource(R.raw.city);

      FileOutputStream out = new FileOutputStream(path + "/city");
      byte buffer[] = new byte[2 * 1024];
      int len = 0;
      while ((len = is.read(buffer)) > 0) {

        out.write(buffer, 0, len);

      }
      out.close();
      is.close();

    }
  }

}