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;
}

}