微信下拉加载

package com.example.weixin;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import java.util.ArrayList;import java.util.List;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicNameValuePair;import android.annotation.SuppressLint;import android.app.ProgressDialog;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.AsyncTask;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v4.app.Fragment;import android.text.TextUtils;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.AbsListView.OnScrollListener;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import com.example.weixin.Weixin.Details;import com.google.gson.Gson;public class Fragment2 extends Fragment {    protected static final String TAG = "Fragment2";    private View view;    private ListView listView;    private int positon = 0;    private String path;    private String result;    Handler handler = new Handler() {        @SuppressLint("NewApi")        public void handleMessage(android.os.Message msg) {            Log.i(TAG, "result...." + result.length());            Bitmap bitmap = (Bitmap) msg.obj;            // 拿到bitmap怎么使用            Bundle data = msg.getData();            // 获取tag imageView身上的标记            String tag = data.getString("tag", null);            // 在listView上根据tag查找控件            ImageView imageView = (ImageView) listView.findViewWithTag(tag);            if (bitmap != null && imageView != null) {                imageView.setImageBitmap(bitmap);            }        };    };    private ArrayList<Details> weixinList;    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,            Bundle savedInstanceState) {        view = inflater.inflate(R.layout.f2_item, container, false);        listView = (ListView) view.findViewById(R.id.f2_listView);        return view;    }    @Override    public void onActivityCreated(Bundle savedInstanceState) {        super.onActivityCreated(savedInstanceState);        // 这里定义一个集合，用来放加载的数据        weixinList = new ArrayList<Details>();        path = "http://v.juhe.cn/weixin/query";        // 加载数据        loadData();        // 设置滑动监听        listView.setOnScrollListener(new OnScrollListener() {            @Override            public void onScrollStateChanged(AbsListView view, int scrollState) {                if (scrollState == OnScrollListener.SCROLL_STATE_IDLE) {                    // 判断一下当前的最后一个条目是不是集合的长度减一                    int lastVisiblePosition = view.getLastVisiblePosition();                    if (lastVisiblePosition == weixinList.size() - 1) {                        // 加载数据，就是再执行一次异步任务                        // 将页面++                        positon++;                        // 再次加载数据                        loadData();                    }                }            }            @Override            public void onScroll(AbsListView view, int firstVisibleItem,                    int visibleItemCount, int totalItemCount) {            }        });    }    /**     * 加载数据，开启异步任务     */    private void loadData() {        MyAsynTask asynTask = new MyAsynTask();        asynTask.execute();    }    private MyAdapter myAdapter;    class MyAsynTask extends AsyncTask<Void, Void, String> {        private ProgressDialog progressDialog;        @Override        protected void onPreExecute() {            super.onPreExecute();            // 展示一个进度条            progressDialog = new ProgressDialog(getActivity());            progressDialog.setTitle("人家正在努力加载");            progressDialog.show();        }        @Override        protected String doInBackground(Void... params) {            try {                // 实例化客户端对象                HttpClient httpClient = new DefaultHttpClient();                // 定义一个post                HttpPost httpPost = new HttpPost(path);                // 如果你不知道如何测试post请求到底通没通                // 你需要自己拼串测试                // http://v.juhe.cn/weixin/query?key=0917c812f187b92e025c9b7c2d4e59b5&pno=2                List<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();                parameters.add(new BasicNameValuePair("key",                        "0917c812f187b92e025c9b7c2d4e59b5"));                parameters                        .add(new BasicNameValuePair("pno", (positon + 1) + ""));                HttpEntity entity = new UrlEncodedFormEntity(parameters);                httpPost.setEntity(entity);                // 执行post请求                HttpResponse httpResponse = httpClient.execute(httpPost);                int statusCode = httpResponse.getStatusLine().getStatusCode();                if (statusCode == 200) {                    InputStream inputStream = httpResponse.getEntity()                            .getContent();                    String streamToStr = streamToStr(inputStream);                    return streamToStr;                }            } catch (Exception e) {                e.printStackTrace();            }            return null;        }        @Override        protected void onPostExecute(String result) {            super.onPostExecute(result);            Fragment2.this.result = result;            // 解析字符串            Gson gson = new Gson();            // json            Weixin fromJson = gson.fromJson(result, Weixin.class);            // 每次数据加载上来，都获取要展示的那个集合            ArrayList<Details> list = fromJson.result.list;            // 添加所有的数据            weixinList.addAll(list);            // 消失进度条            progressDialog.dismiss();            // 第一次的时候，adapter是null，创建，设置数据适配器            if (myAdapter == null) {                myAdapter = new MyAdapter();                listView.setAdapter(myAdapter);            } else {                // 之后每一次都刷新数据                myAdapter.notifyDataSetChanged();            }        }    }    /**     * 流转串     *      * @param inputStream     * @return     */    public static String streamToStr(InputStream inputStream) {        try {            byte[] buffer = new byte[1024];            int len = 0;            ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();            while ((len = inputStream.read(buffer)) != -1) {                arrayOutputStream.write(buffer, 0, len);            }            return arrayOutputStream.toString();        } catch (IOException e) {            e.printStackTrace();        }        return null;    }    class MyAdapter extends BaseAdapter {        @Override        public int getCount() {            return weixinList.size();        }        @Override        public Object getItem(int position) {            return weixinList.get(position);        }        @Override        public long getItemId(int position) {            return position;        }        @Override        public View getView(int position, View convertView, ViewGroup parent) {            ViewHolder viewHolder = null;            if (convertView == null) {                convertView = View.inflate(getActivity(), R.layout.lv_item,                        null);                viewHolder = new ViewHolder();                convertView.setTag(viewHolder);                viewHolder.lv_imageView = (ImageView) convertView                        .findViewById(R.id.lv_imageView);                viewHolder.lv_textView = (TextView) convertView                        .findViewById(R.id.lv_textView);            } else {                viewHolder = (ViewHolder) convertView.getTag();            }            viewHolder.lv_textView.setText(weixinList.get(position).title);            // bitmapUtils展示图片            // ----------------------------------------------------            // BitmapUtils bitmapUtils = new BitmapUtils(getActivity());            // String url = list.get(position).firstImg;            // if(TextUtils.isEmpty(url)){            // viewHolder.lv_imageView.setImageResource(R.drawable.ic_launcher);            // }else{            // url = url.substring(0, url.lastIndexOf("/"));            // // 正常的url            // url = Images.imageThumbUrls[position];            // bitmapUtils.display(viewHolder.lv_imageView, url);            // }            // ---------------------------------------------------------            // final String url = Images.imageThumbUrls[position];            final String firstImg = weixinList.get(position).firstImg;            if (TextUtils.isEmpty(firstImg)) {                viewHolder.lv_imageView                        .setImageResource(R.drawable.ic_launcher);            } else {                // 给imageView设置tag 设置标记                viewHolder.lv_imageView.setTag(firstImg);                new Thread() {                    public void run() {                        getBitmap(firstImg);                    };                }.start();            }            return convertView;        }        class ViewHolder {            ImageView lv_imageView;            TextView lv_textView;        }    }    /**     * 根据路径获取图片     *      * @param path     */    public void getBitmap(String path) {        try {            URL url = new URL(path);            HttpURLConnection openConnection = (HttpURLConnection) url                    .openConnection();            openConnection.setConnectTimeout(5000);            openConnection.setReadTimeout(5000);            int responseCode = openConnection.getResponseCode();            if (responseCode == 200) {                InputStream inputStream = openConnection.getInputStream();                Bitmap decodeStream = BitmapFactory.decodeStream(inputStream);                Message obtain = Message.obtain();                obtain.what = 1;                // 将imageView身上绑的tag传递给handler                Bundle data = new Bundle();                data.putString("tag", path);                obtain.setData(data);                obtain.obj = decodeStream;                handler.sendMessage(obtain);            }        } catch (Exception e) {            e.printStackTrace();        }    }}