Android开源项目PullToRefresh下拉刷新功能详解2

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" ><!-- The PullToRefreshGridView replaces a standard GridView widget. --> <com.handmark.pulltorefresh.library.PullToRefreshGridView  xmlns:ptr="http://schemas.android.com/apk/res-auto"  android:id="@+id/pull_refresh_grid"  android:layout_height="fill_parent"  android:layout_width="fill_parent"  android:numColumns="auto_fit"  android:verticalSpacing="1dp"  android:horizontalSpacing="1dp"  android:columnWidth="100dp"  android:stretchMode="columnWidth"  android:gravity="fill"  ptr:ptrMode="both"  ptr:ptrDrawable="@drawable/ic_launcher" /></LinearLayout>

 /**  *设置下拉刷新的view，设置双向监听器   */ private void initPTRGrideView() {  // 得到下拉刷新的GridView  mPullRefreshGridView = (PullToRefreshGridView) findViewById(R.id.pull_refresh_grid);  // 设置监听器，这个监听器是可以监听双向滑动的，这样可以触发不同的事件  mPullRefreshGridView.setOnRefreshListener(new OnRefreshListener2<GridView>() {   @Override   public void onPullDownToRefresh(PullToRefreshBase<GridView> refreshView) {    Toast.makeText(getApplicationContext(), "下拉", Toast.LENGTH_SHORT).show();    new GetDataTask(mPullRefreshGridView, mAdapter, mListItems).execute();   }   @Override   public void onPullUpToRefresh(PullToRefreshBase<GridView> refreshView) {    Toast.makeText(getApplicationContext(), "上拉", Toast.LENGTH_SHORT).show();    new GetDataTask(mPullRefreshGridView, mAdapter, mListItems).execute();   }  }); }

 //链表数组对象，用来方便添加string对象 private LinkedList<String> mListItems; //用来下拉刷新的控件 private PullToRefreshGridView mPullRefreshGridView; //真正用到的控件，它被隐含到PullToRefreshGridView中，所以需要找出来才能使用 private GridView mGridView; //定义GridView的适配器 private ArrayAdapter<String> mAdapter;

 /**  * 设置GridView，首先找到它，然后设置适配器  */ private void initGrideView() {  mGridView = mPullRefreshGridView.getRefreshableView();  //定义String数组，然后把它放到LinkedList中，之后只要在异步任务中用LinkedList就可以添加开头和结尾的数据了  String []data = new String[] {"android","ios","wp","java","c++","c#"};  mListItems = new LinkedList<String>();  mListItems.addAll(Arrays.asList(data));  //当适配器中没有数据的时候显示的东西，这里因为我给适配器中填充了string数组，所以不会显示“这里很空，下拉刷新试试”  TextView tv = new TextView(this);  tv.setGravity(Gravity.CENTER);  tv.setText("这里很空，下拉刷新试试");  //当界面为空的时候显示的视图  mPullRefreshGridView.setEmptyView(tv);  //设置适配器  mAdapter = new ArrayAdapter<String>(this,     android.R.layout.simple_list_item_1, mListItems);  mGridView.setAdapter(mAdapter); }

package com.kale.ptrgridview;import java.util.LinkedList;import android.os.AsyncTask;import android.widget.ArrayAdapter;import com.handmark.pulltorefresh.library.PullToRefreshBase.Mode;import com.handmark.pulltorefresh.library.PullToRefreshGridView;/** * @author:Jack Tony * @tips :通过异步任务来加载网络中的数据，进行更新 * @date :2014-10-14 */public class GetDataTask extends AsyncTask<Void, Void, Void>{ private PullToRefreshGridView mPullRefreshGridView; private ArrayAdapter<String> mAdapter; private LinkedList<String> mListItems;   public GetDataTask(PullToRefreshGridView gridView,   ArrayAdapter<String> adapter,LinkedList<String> listItems) {  // TODO 自动生成的构造函数存根  mPullRefreshGridView = gridView;  mAdapter = adapter;  mListItems = listItems; }  @Override protected Void doInBackground(Void... params) {  //模拟请求，舒眠2秒钟  try {   Thread.sleep(2000);  } catch (InterruptedException e) {  }  return null; }  @Override protected void onPostExecute(Void result) {  // TODO 自动生成的方法存根  super.onPostExecute(result);    //得到当前的模式，来判断数据应该加载到哪个位置  Mode mode = mPullRefreshGridView.getCurrentMode();  if(mode == Mode.PULL_FROM_START) {   mListItems.addFirst("这是刷新出来的数据");  }  else {   mListItems.addLast("这是刷新出来的数据");  }  // 通知数据改变了  mAdapter.notifyDataSetChanged();  // 加载完成后停止刷新  mPullRefreshGridView.onRefreshComplete();   } }

package com.kale.ptrgridview;import java.util.Arrays;import java.util.LinkedList;import android.app.Activity;import android.os.Bundle;import android.view.Gravity;import android.widget.ArrayAdapter;import android.widget.GridView;import android.widget.TextView;import android.widget.Toast;import com.handmark.pulltorefresh.library.PullToRefreshBase;import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener2;import com.handmark.pulltorefresh.library.PullToRefreshGridView;public class MainActivity extends Activity {  //链表数组对象，用来方便添加string对象 private LinkedList<String> mListItems; //用来下拉刷新的控件 private PullToRefreshGridView mPullRefreshGridView; //真正用到的控件，它被隐含到PullToRefreshGridView中，所以需要找出来才能使用 private GridView mGridView; //定义GridView的适配器 private ArrayAdapter<String> mAdapter;  @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);    initView(); } private void initView() {  // TODO 自动生成的方法存根  initPTRGrideView();  initGrideView(); } /**  *设置下拉刷新的view，设置双向监听器   */ private void initPTRGrideView() {  // 得到下拉刷新的GridView  mPullRefreshGridView = (PullToRefreshGridView) findViewById(R.id.pull_refresh_grid);  // 设置监听器，这个监听器是可以监听双向滑动的，这样可以触发不同的事件  mPullRefreshGridView.setOnRefreshListener(new OnRefreshListener2<GridView>() {   @Override   public void onPullDownToRefresh(PullToRefreshBase<GridView> refreshView) {    Toast.makeText(getApplicationContext(), "下拉", Toast.LENGTH_SHORT).show();    new GetDataTask(mPullRefreshGridView, mAdapter, mListItems).execute();   }   @Override   public void onPullUpToRefresh(PullToRefreshBase<GridView> refreshView) {    Toast.makeText(getApplicationContext(), "上拉", Toast.LENGTH_SHORT).show();    new GetDataTask(mPullRefreshGridView, mAdapter, mListItems).execute();   }  }); }  /**  * 设置GridView，首先找到它，然后设置适配器  */ private void initGrideView() {  mGridView = mPullRefreshGridView.getRefreshableView();  //定义String数组，然后把它放到LinkedList中，之后只要在异步任务中用LinkedList就可以添加开头和结尾的数据了  String []data = new String[] {"android","ios","wp","java","c++","c#"};  mListItems = new LinkedList<String>();  mListItems.addAll(Arrays.asList(data));  //当适配器中没有数据的时候显示的东西，这里因为我给适配器中填充了string数组，所以不会显示“这里很空，下拉刷新试试”  TextView tv = new TextView(this);  tv.setGravity(Gravity.CENTER);  tv.setText("这里很空，下拉刷新试试");  //当界面为空的时候显示的视图  mPullRefreshGridView.setEmptyView(tv);  //设置适配器  mAdapter = new ArrayAdapter<String>(this,     android.R.layout.simple_list_item_1, mListItems);  mGridView.setAdapter(mAdapter); }  }