Android ListView数据的分批显示功能

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical" >  <RelativeLayout     android:layout_width="match_parent"   android:layout_height="wrap_content"    >    <TextView  style="@style/TitleStyle"   android:text="黑名单管理"    />    <Button       android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_alignParentRight="true"    android:text="添加"      />  </RelativeLayout>  <FrameLayout     android:layout_width="match_parent"   android:layout_height="match_parent"   android:layout_weight="11"    >    <LinearLayout       android:id="@+id/ll_pb"      android:layout_width="match_parent"    android:layout_height="wrap_content"    android:gravity="center"    android:visibility="invisible"    android:orientation="vertical"    >    <ProgressBar      android:layout_width="wrap_content"    android:layout_height="wrap_content"      />    <TextView       android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="玩命加载中..."      />    </LinearLayout>   <include      android:id="@+id/list_view_callsafe"     layout="@layout/list_view_callsafe"/>  </FrameLayout></LinearLayout>逻辑文件，实现页面的分页显示，监听ListView的滑动事件，滑动的时候就更新数据

package com.ldw.safe.Activity;import java.util.List;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.AbsListView.OnScrollListener;import android.widget.EditText;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;import com.ldw.safe.R;import com.ldw.safe.adapter.MyBaseAdapter;import com.ldw.safe.bean.BlackNumberInfo;import com.ldw.safe.db.dao.BlackNumberDao;public class CallSafeActivity extends Activity { private ListView list_view_callsafe; private List<BlackNumberInfo> blackNumberInfos; private LinearLayout ll_pb; private BlackNumberDao dao; private CallSafeAdapter adapter; private int totalNumber;//总的条数 private int mStartIndex = 0;//开始加载的位置 private int maxCount = 20;//每页加载多少数据 @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_call_safe2);    initUi();    initData(); } //初始化数据 private Handler handler = new Handler(){ @Override    public void handleMessage(Message msg) {  //数据初始化结束，关闭家在全的展示  ll_pb.setVisibility(View.INVISIBLE);  //防止适配器一直刷新  if(adapter == null){  adapter = new CallSafeAdapter(blackNumberInfos, CallSafeActivity.this);  //配置适配器  list_view_callsafe.setAdapter(adapter);  }else{   adapter.notifyDataSetChanged();  } } }; private EditText et_page_number; //初始化数据 private void initData() { //防止阻塞主线程，在子线程中初始化数据（后期数据会很多） new Thread(){  @Override  public void run(){  dao = new BlackNumberDao(CallSafeActivity.this);   //一共有多少条数据     totalNumber = dao.getTotalNumber();  //分批加载数据     if(blackNumberInfos == null){      //第一次加载      blackNumberInfos = dao.findPar2(mStartIndex, maxCount);     }else{      //把后面的数据。追加到blackNumberInfos集合里面。防止黑名单被覆盖      blackNumberInfos.addAll(dao.findPar2(mStartIndex, maxCount));     }  handler.sendEmptyMessage(0);  } }.start(); } //初始化UI private void initUi() { ll_pb = (LinearLayout) findViewById(R.id.ll_pb);    //初始化的时候展示加载的圆圈    ll_pb.setVisibility(View.VISIBLE); list_view_callsafe = (ListView) findViewById(R.id.list_view_callsafe); //设置listView的滚动监听器 list_view_callsafe.setOnScrollListener(new OnScrollListener(){      //状态改变时候回调的方法      /*       * @param scrollState 表示滚动的状态       *AbsListView.OnScrollListener.SCROLL_STATE_IDLE 闲置状态       *AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL 手指触摸的时候的状态       *AbsListView.OnScrollListener.SCROLL_STATE_FLING 惯性       */  @Override  public void onScrollStateChanged(AbsListView view, int scrollState) {        switch (scrollState) {        case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:          //获取到最后一条显示的数据条数          int lastVisiblePosition = list_view_callsafe.getLastVisiblePosition();          System.out.println("lastVisiblePosition==========" + lastVisiblePosition);            if(lastVisiblePosition == blackNumberInfos.size() - 1){//判断最后一个数据是不是每页显示的数据-1              // 加载更多的数据。 更改加载数据的开始位置              mStartIndex += maxCount;              if (mStartIndex >= totalNumber) {                Toast.makeText(getApplicationContext(),                    "没有更多的数据了。", Toast.LENGTH_SHORT).show();                return;              }              initData();            }          break;      }  }  //listview滚动的时候调用的方法      //时时调用。当我们的手指触摸的屏幕的时候就调用  @Override  public void onScroll(AbsListView view, int firstVisibleItem,   int visibleItemCount, int totalItemCount) {  // TODO Auto-generated method stub  } }); } //对代码进行优化，继承自定义MyBaseAdapter，MyBaseAdapter继承自BaseAdapter封装一些常用的方法 private class CallSafeAdapter extends MyBaseAdapter<BlackNumberInfo>{ private CallSafeAdapter(List lists, Context mContext){  super(lists, mContext); } @Override public View getView(int position, View convertView, ViewGroup parent) {  //谷歌推出的优化方案  ViewHolder holder;  if(convertView == null){  convertView = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);  holder = new ViewHolder();  holder.tv_number = (TextView) convertView.findViewById(R.id.tv_number);  holder.tv_mode = (TextView) convertView.findViewById(R.id.tv_mode);  holder.iv_delete = (ImageView) convertView.findViewById(R.id.iv_delete);  convertView.setTag(holder);  }else{  holder = (ViewHolder) convertView.getTag();  }  holder.tv_number.setText(lists.get(position).getNumber());  String mode = lists.get(position).getMode();  if(mode.equals("1")){  holder.tv_mode.setText("电话和短信拦截");  }else if(mode.equals("2")){  holder.tv_mode.setText("电话拦截");  }else if(mode.equals("3")){  holder.tv_mode.setText("短信拦截");  }  final BlackNumberInfo info = lists.get(position);  //监听删除数据按钮，删除数据  holder.iv_delete.setOnClickListener(new OnClickListener(){  @Override  public void onClick(View v) {   String number = info.getNumber();   boolean result = dao.delete(number);   if(result){   Toast.makeText(CallSafeActivity.this, "删除成功", Toast.LENGTH_SHORT).show();   lists.remove(info);   //更新ListView   adapter.notifyDataSetChanged();   }else{   Toast.makeText(CallSafeActivity.this, "删除失败", Toast.LENGTH_SHORT).show();   }  }  });  return convertView;  /*  //谷歌推出的优化方案  ViewHolder holder;  if(convertView == null){  convertView = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);  holder = new ViewHolder();  holder.tv_number = (TextView) convertView.findViewById(R.id.tv_number);  holder.tv_mode = (TextView) convertView.findViewById(R.id.tv_mode);  convertView.setTag(holder);  }else{  holder = (ViewHolder) convertView.getTag();  }  holder.tv_number.setText(blackNumberInfos.get(position).getNumber());  String mode = blackNumberInfos.get(position).getMode();  if(mode.equals("1")){  holder.tv_mode.setText("电话和短信拦截");  }else if(mode.equals("2")){  holder.tv_mode.setText("电话拦截");  }else if(mode.equals("3")){  holder.tv_mode.setText("短信拦截");  }  return convertView;  */  /*初步的优化  convertView = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);  TextView tv_number = (TextView) convertView.findViewById(R.id.tv_number);  TextView tv_mode = (TextView) convertView.findViewById(R.id.tv_mode);  tv_number.setText(blackNumberInfos.get(position).getNumber());  String mode = blackNumberInfos.get(position).getMode();  if(mode.equals("1")){  tv_mode.setText("电话和短信拦截");  }else if(mode.equals("2")){  tv_mode.setText("电话拦截");  }else if(mode.equals("3")){  tv_mode.setText("短信拦截");  }  return convertView;  */  /*传统的方式  View view = View.inflate(CallSafeActivity.this, R.layout.item_call_safe, null);  TextView tv_number = (TextView) view.findViewById(R.id.tv_number);  TextView tv_mode = (TextView) view.findViewById(R.id.tv_mode);  tv_number.setText(blackNumberInfos.get(position).getNumber());  String mode = blackNumberInfos.get(position).getMode();  if(mode.equals("1")){  tv_mode.setText("电话和短信拦截");  }else if(mode.equals("2")){  tv_mode.setText("电话拦截");  }else if(mode.equals("3")){  tv_mode.setText("短信拦截");  }  return view;  */ }  } static class ViewHolder{ TextView tv_number; TextView tv_mode; ImageView iv_delete; }}