44、gridview实现下拉刷新、上拉加载更多（最简单实现上下拉操作的开源工程！）

1、工程加入以下两个文件夹：（参考：https://github.com/jingchenUSTC/PullToRefreshAndLoad） （待会我会将demo打包上传）

2、这个demo只有一个activity，该activity就是显示一个支持上拉加载更多的gridview：

 package com.example.test_textview;

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

 import com.jingchen.pulltorefresh.MyListener;
 import com.jingchen.pulltorefresh.PullToRefreshLayout;

 import android.app.Activity;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Handler;
 import android.widget.GridView;
 import android.widget.ListView;

 public class MainActivity extends Activity {

     public String tag = "MainActivity";

     public static Context ctxt = null;
     public static Handler handler = null;

     public GridView gridview = null;
     public girdviewAdapter adapter = null;
     public List<Integer> listGridview = null;

     public static int index = 0;

     public static final int UPDATE_GRIDVIEW_LOAD_MORE = 0;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         init();

         widgetConfigure();

     }

     public void init()
     {
         ctxt = getApplicationContext();

         gridview = (GridView)findViewById(R.id.gridview_test);

         handler = new Handler()
         {
             public void handleMessage(android.os.Message msg)
             {
                 switch(msg.what)
                 {
                 case UPDATE_GRIDVIEW_LOAD_MORE:

                     index++;
                     for(int k=0;k<12;k++)
                     {
                         int t = 12*index+k;
                         listGridview.add(t);
                       }

　　　　　　　　　　　　　  adapter.notifyDataSetChanged();

　　　　　　　　　　　　　　gridview.smoothScrollToPosition(adapter.getCount());

                     break;
                 }
             };
         };

         listGridview = new ArrayList<Integer>();
         for(int k=0;k<12;k++)
         {
             listGridview.add(k);
         }
         adapter = new girdviewAdapter(listGridview,ctxt,handler);

     }

     public void widgetConfigure()
     {
         gridview.setAdapter(adapter);

         ((PullToRefreshLayout) findViewById(R.id.refresh_view)).setOnRefreshListener(new MyListener());

     }
 }

3、activity_main xml文件：

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:background="@color/Constrast_3"
     android:orientation="vertical"
     android:padding="20dp" >

         <com.jingchen.pulltorefresh.PullToRefreshLayout
                     android:id="@+id/refresh_view"  <!-- 这个自定义布局，可以通过检测手势，判断是上拉还是下拉，然后将结果告诉listener-->
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"
                     android:layout_alignParentTop="true"
                     >

                     <include layout="@layout/refresh_head" />   <!-- 这个是下拉刷新的头，引用的1中git的文件-->

                     <com.jingchen.pulltorefresh.pullableview.PullableGridView
                             android:id="@+id/gridview_test"
                             android:layout_width="match_parent"
                             android:layout_height="wrap_content"
                             android:numColumns="4"
                             android:verticalSpacing="12dp"
                             android:horizontalSpacing="14dp"
                             android:gravity="center"
                         />

                     <include layout="@layout/load_more" />    <!-- 这个是上拉加载更多的尾部，引用的1中git的文件-->

  </com.jingchen.pulltorefresh.PullToRefreshLayout>   </LinearLayout>

3、refreshView通过检测手势，判断用户操作是上拉还是下拉，进而通过listener来进行相应的数据操作：

 package com.jingchen.pulltorefresh;

 import android.os.Handler;
 import android.os.Message;

 import com.example.test_textview.MainActivity;
 import com.jingchen.pulltorefresh.PullToRefreshLayout.OnRefreshListener;

 public class MyListener implements OnRefreshListener
 {

     @Override
     public void onRefresh(final PullToRefreshLayout pullToRefreshLayout)
     {

         pullToRefreshLayout.refreshFinish(PullToRefreshLayout.SUCCEED);

     /*    // 下拉刷新操作
         new Handler()
         {
             @Override
             public void handleMessage(Message msg)
             {
                 // 千万别忘了告诉控件刷新完毕了哦！
                 pullToRefreshLayout.refreshFinish(PullToRefreshLayout.SUCCEED);
             }
         }.sendEmptyMessageDelayed(0, 5000);*/
     }

     @Override
     public void onLoadMore(final PullToRefreshLayout pullToRefreshLayout)
     {

         // 加载操作
         new Handler()
         {
             @Override
             public void handleMessage(Message ms1g)
             {
                 // 千万别忘了告诉控件加载完毕了哦！
                 pullToRefreshLayout.loadmoreFinish(PullToRefreshLayout.SUCCEED);

                 Message msg = new Message();
                 msg.what = MainActivity.UPDATE_GRIDVIEW_LOAD_MORE;
                 MainActivity.handler.sendMessage(msg);
             }
         }.sendEmptyMessageDelayed(0, 5000);

     }

 }

需要看demo整个工程的请跳转：http://pan.baidu.com/s/1hqjci6w