ListView 实现像Android Market那样 分页加载 滚动加载

package zy.lucifer.ListViewScroll;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AbsListView.OnScrollListener;
import android.widget.LinearLayout.LayoutParams;
public class ListViewScroll extends Activity {
 /** Called when the activity is first created. */
 private LayoutParams mLayoutParams = new LinearLayout.LayoutParams(
   LinearLayout.LayoutParams.WRAP_CONTENT,
   LinearLayout.LayoutParams.WRAP_CONTENT);
 /**
  * 设置布局显示目标最大化属性
  */
 private LayoutParams FFlayoutParams = new LinearLayout.LayoutParams(
   LinearLayout.LayoutParams.FILL_PARENT,
   LinearLayout.LayoutParams.FILL_PARENT);
 ListView listView ;
 private int lastItem = 0;
 LinearLayout loadingLayout;
 private listViewAdapter adapter;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  listView = (ListView) findViewById(R.id.myList);
  
  Log.i("test", "onCreate(Bundle savedInstanceState)>>>>>>>>>>>>>>>");
  // 线性布局
  LinearLayout layout = new LinearLayout(this);
  // 设置布局 水平方向
  layout.setOrientation(LinearLayout.HORIZONTAL);
  // 进度条
  ProgressBar progressBar = new ProgressBar(this);
  // 进度条显示位置
  progressBar.setPadding(0, 0, 15, 0);
  // 把进度条加入到layout中
  layout.addView(progressBar, mLayoutParams);
  // 文本内容
  TextView textView = new TextView(this);
  textView.setText("加载中...");
  textView.setGravity(Gravity.CENTER_VERTICAL);
  // 把文本加入到layout中
  layout.addView(textView, FFlayoutParams);
  // 设置layout的重力方向，即对齐方式是
  layout.setGravity(Gravity.CENTER);
  // 设置ListView的页脚layout
  loadingLayout = new LinearLayout(this);
  loadingLayout.addView(layout, mLayoutParams);
  loadingLayout.setGravity(Gravity.CENTER);
  listView.addFooterView(loadingLayout);
  adapter = new listViewAdapter();
  listView.setAdapter(adapter);
  listView.setOnScrollListener(new OnScrollListener() {