Android PullToRefresh （GridView 下拉刷新上拉加载）

做这个需要自己去git hub上下载个 pull-to-refresh 里面有个library为依赖包自己导到自己的项目中

（下载地址：https://github.com/chrisbanes/Android-PullToRefresh）

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <!-- 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_width="match_parent"
        android:layout_height="match_parent"
        android:numColumns="2"
        ptr:ptrDrawable="@drawable/ic_launcher"
        ptr:ptrMode="both" />

</LinearLayout>

我们添加了一个属性：ptr:ptrMode="both" ，意思：上拉和下拉都支持。

可选值为：disabled（禁用下拉刷新），pullFromStart（仅支持下拉刷新），pullFromEnd（仅支持上拉刷新），both（二者都支持），manualOnly（只允许手动触发）

gridview中item布局

gridview.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
        android:id="@+id/image_src"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/text_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/image_src"
        android:text="TextView" />

</RelativeLayout>

MainActivity.java

package com.bawei.myxgridview;

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

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.format.DateUtils;
import android.util.Log;
import android.widget.BaseAdapter;
import android.widget.GridView;

import com.bawei.vo.Good;
import com.bawei.vo.MyData;

import com.google.gson.Gson;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener2;
import com.handmark.pulltorefresh.library.PullToRefreshGridView;

public class MainActivity extends Activity {

    private PullToRefreshGridView mPullRefreshListView;
    // 网址
    private String URL = "http://api.expoon.com/AppNews/getNewsList/type/1/p/";
    List<MyData> list = new ArrayList<MyData>();
    private BaseAdapter adapter;
    int z = 10;
    int p = 10;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 找控件
        mPullRefreshListView = (PullToRefreshGridView) findViewById(R.id.pull_refresh_grid);
        // 刚进入初次加载
        new GetDataTask().execute(URL + z);
        // 监听
        mPullRefreshListView
                .setOnRefreshListener(new OnRefreshListener2<GridView>() {
                    // 下拉刷新加载
                    @Override
                    public void onPullDownToRefresh(
                            PullToRefreshBase<GridView> refreshView) {
                        Log.e("TAG", "onPullDownToRefresh"); // Do work to
                        // 刷新时间
                        String label = DateUtils.formatDateTime(
                                getApplicationContext(),
                                System.currentTimeMillis(),
                                DateUtils.FORMAT_SHOW_TIME
                                        | DateUtils.FORMAT_SHOW_DATE
                                        | DateUtils.FORMAT_ABBREV_ALL);

                        // Update the LastUpdatedLabel
                        refreshView.getLoadingLayoutProxy()
                                .setLastUpdatedLabel(label);
                        // 页数
                        z = z - 1;
                        // AsyncTask异步交互加载数据
                        new GetDataTask().execute(URL + z);
                    }

                    // 上拉加载跟多
                    @Override
                    public void onPullUpToRefresh(
                            PullToRefreshBase<GridView> refreshView) {
                        Log.e("TAG", "onPullUpToRefresh"); // Do work to refresh

                        // 页数
                        p = p + 1;
                        // AsyncTask异步交互加载数据
                        new GetDataTask2().execute(URL + p);
                    }
                });
    }

    // 下拉刷新加载数据
    private class GetDataTask extends AsyncTask<String, Integer, String> {

        private String s;

        @Override
        protected String doInBackground(String... params) {

            String url = params[0];
            // 请求数据
            s = NetWorkUtil.loginCheck_Get_HttpClient(url);

            return s;
        }

        @Override
        protected void onPostExecute(String result) {
            // 解析
            Gson gson = new Gson();

            Good good = gson.fromJson(result, Good.class);
            List<MyData> data = good.getData();

            list = data;
            // 适配
            adapter = new Adper(MainActivity.this, list);
            mPullRefreshListView.setAdapter(adapter);
            // 刷新适配器
            adapter.notifyDataSetChanged();
            // 关闭刷新下拉
            mPullRefreshListView.onRefreshComplete();

        }
    }

    // 上拉加载更多
    private class GetDataTask2 extends AsyncTask<String, Integer, String> {

        private String s;

        @Override
        protected String doInBackground(String... params) {

            String url = params[0];
            // 请求数据
            s = NetWorkUtil.loginCheck_Get_HttpClient(url);

            return s;
        }

        @Override
        protected void onPostExecute(String result) {
            // 解析
            Gson gson = new Gson();
            Good good = gson.fromJson(result, Good.class);
            List<MyData> data = good.getData();
            list.addAll(data);
            // 刷新适配器
            adapter.notifyDataSetChanged();
            // Call onRefreshComplete when the list has been refreshed.
            // 关闭上拉加载
            mPullRefreshListView.onRefreshComplete();
        }
    }
}

请求数据NetWorkUtil.java

package com.bawei.myxgridview;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.util.EntityUtils;

public class NetWorkUtil {

    public static String loginCheck_Get_HttpClient(String url) {
        // TODO Auto-generated method stub
String result = "";
        
        HttpGet get = new HttpGet(url);//创建httpClient的get请求对象
        //设置请求参数
        HttpParams params = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(params, 5*1000);
        HttpConnectionParams.setSoTimeout(params, 5*1000);
        
        HttpClient client = new DefaultHttpClient(params);//创建HttpClient对象
        
        try {
            HttpResponse res = client.execute(get);//执行请求，获得结果
            if(res.getStatusLine().getStatusCode() == 200){
                HttpEntity entity = res.getEntity();//获得相应结果，是一个HttpEntity对象
                result = EntityUtils.toString(entity, "utf-8");//转换为字符串
            }
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return result;
    }

}

VO类   两个

Good.java

package com.bawei.vo;

import java.util.List;

public class Good {
    private List<MyData> data;

    public Good(List<MyData> data) {
        super();
        this.data = data;
    }

    @Override
    public String toString() {
        return "Good [data=" + data + "]";
    }

    public List<MyData> getData() {
        return data;
    }

    public void setData(List<MyData> data) {
        this.data = data;
    }

    public Good() {
        super();
    }

}

MyData.java

package com.bawei.vo;

public class MyData {
private String news;
private String news_summary;
private String news_title;
private String pic_url;
public String getNews() {
    return news;
}
public void setNews(String news) {
    this.news = news;
}
public String getNews_summary() {
    return news_summary;
}
public void setNews_summary(String news_summary) {
    this.news_summary = news_summary;
}
public String getNews_title() {
    return news_title;
}
public void setNews_title(String news_title) {
    this.news_title = news_title;
}
public String getPic_url() {
    return pic_url;
}
public void setPic_url(String pic_url) {
    this.pic_url = pic_url;
}
@Override
public String toString() {
    return "MyData [news=" + news + ", news_summary=" + news_summary
            + ", news_title=" + news_title + ", pic_url=" + pic_url + "]";
}
public MyData(String news, String news_summary, String news_title,
        String pic_url) {
    super();
    this.news = news;
    this.news_summary = news_summary;
    this.news_title = news_title;
    this.pic_url = pic_url;
}
public MyData() {
    super();
}

}

适配器  Adper.java

package com.bawei.myxgridview;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.bawei.vo.MyData;
import com.lidroid.xutils.BitmapUtils;

public class Adper extends BaseAdapter {
    Context context;
    List<MyData> list;
    public Adper(Context context, List<MyData> list) {
        // TODO Auto-generated constructor stub
    this.context=context;
    this.list=list;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int arg0, View convertView, ViewGroup arg2) {
        // TODO Auto-generated method stub
        viewholder vh;
        if(convertView==null){
            convertView=LayoutInflater.from(context).inflate(R.layout.gridview, null);
            vh=new viewholder();
            vh.image=(ImageView) convertView.findViewById(R.id.image_src);
            vh.title=(TextView) convertView.findViewById(R.id.text_title);
            convertView.setTag(vh);
        }else{
            vh=(viewholder) convertView.getTag();
        }
        BitmapUtils bitmapUtils=new BitmapUtils(context);
        bitmapUtils.display(vh.image,list.get(arg0).getPic_url());
        vh.title.setText(list.get(arg0).getNews_title());
        return convertView;
    }
    class viewholder{
        ImageView image;
        TextView title;
    }

}