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-->

29 </com.jingchen.pulltorefresh.PullToRefreshLayout> 30 31 </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