Android实战教程第四十三篇之上拉加载与下拉刷新

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent" >   <me.maxwin.view.XListView   android:id="@+id/xlv"   android:layout_width="match_parent"   android:layout_height="match_parent" />  </RelativeLayout> 

package com.itydl.xlistviewdemo;  import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List;  import me.maxwin.view.XListView; import me.maxwin.view.XListView.IXListViewListener; import android.app.Activity; import android.graphics.Color; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.os.SystemClock; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView;  public class MainActivity extends Activity {   private XListView mXListView;  List<String> datas = new ArrayList<String>();  private MyAdapter adapter;  private boolean isLoadMore;//是否正在加载更多数据的标记    private long preTime;//上一次刷新的当前系统时间毫秒值  private Handler handler = new Handler(){   public void handleMessage(android.os.Message msg) {    if(isLoadMore){     //消息是上拉加载更多     initDatas();     isLoadMore = false;     //刷新完毕，关闭上拉加载效果     mXListView.stopLoadMore();    }else{     //消息是下拉刷新     datas.clear();     initDatas();     //刷新完毕，关闭下拉刷新效果     mXListView.stopRefresh();    }    // 刷新listview    adapter.notifyDataSetChanged();   };  };   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   initDatas();   mXListView = (XListView) findViewById(R.id.xlv);   //设置适配器到ListView   adapter = new MyAdapter();   mXListView.setAdapter(adapter);   initListener();  }    private void initListener() {   //设置可以下拉刷新，默认就是true   mXListView.setPullRefreshEnable(true);      //设置可以上拉加载，默认是false   mXListView.setPullLoadEnable(true);      mXListView.setXListViewListener(new IXListViewListener() {        @Override    public void onRefresh() {     // 下拉刷新,实际发送Handler     //发送一个空消息，延迟两秒后告知刷新数据     handler.sendMessageDelayed(Message.obtain(), 2000);     //添加上一次刷新的时间：     if(preTime != 0){      mXListView.setRefreshTime(refreshData(preTime));     }     preTime = System.currentTimeMillis();    }     private String refreshData(long preTime) {     return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(preTime));    }     @Override    public void onLoadMore() {     //标记正在加载更多，发送Handler     isLoadMore = true;     handler.sendMessageDelayed(Message.obtain(), 2000);    }   });  }   /**模拟网络数据*/  private void initDatas() {   //实际开发应该子线程执行   for (int i = 0; i < 50; i++) {    datas.add("我是第" + i + "条数据");   }  }   private class MyAdapter extends BaseAdapter{    @Override   public int getCount() {    if(datas != null){     return datas.size();    }    return 0;   }    @Override   public Object getItem(int position) {    if(datas != null){     return datas.get(position);    }    return null;   }    @Override   public long getItemId(int position) {    return position;   }    @Override   public View getView(int position, View convertView, ViewGroup parent) {    //模拟item为TextView    TextView textView = new TextView(MainActivity.this);    textView.setText(getItem(position)+"");    textView.setTextColor(Color.GREEN);    return textView;   }  } }