上拉刷新下拉加载

1 package com.lixu.listviewrefresh;  2   3 import java.util.ArrayList;  4 import java.util.HashMap;  5 import java.util.Random;  6   7 import com.lixu.listviewrefresh.Loadnetimage.OnLoadnetimageListener;  8 import com.lixu.listviewrefresh.MyRefreshListview.OnRefreshListener;  9 import android.annotation.SuppressLint; 10 import android.app.Activity; 11 import android.app.ProgressDialog; 12 import android.content.Context; 13 import android.graphics.Bitmap; 14 import android.graphics.BitmapFactory; 15 import android.os.AsyncTask; 16 import android.os.Bundle; 17 import android.util.Log; 18 import android.view.LayoutInflater; 19 import android.view.View; 20 import android.view.ViewGroup; 21 import android.widget.ArrayAdapter; 22 import android.widget.ImageView; 23 import android.widget.ListView; 24 import android.widget.TextView; 25  26 public class MainActivity extends Activity { 27     private static final String KEY_IMAGE = "image_key"; 28     private static final String KEY_TEXT = "text_key"; 29  30     private static final String CACHE_KEY_IMAGE = "cache_image_key"; 31     private static final String CACHE_KEY_TEXT = "cache_text_key"; 32     // 原始数据 33     private ArrayList<HashMap<String, Object>> data; 34     // 缓存队列 35     private ArrayList<HashMap<String, Object>> cache; 36  37     private ArrayAdapter<String> mMyAdapter; 38  39     private MyRefreshListview lv; 40  41     private Activity activity; 42     private Random random = new Random(); 43     // 图片网络地址 44     private String[] image_urls = { "http://img0.bdstatic.com/img/image/shouye/mxh007.jpg", 45             "http://f.hiphotos.baidu.com/image/h%3D360/sign=1c9a50843ec79f3d90e1e2368aa0cdbc/f636afc379310a5566becb8fb24543a982261036.jpg", 46             "http://h.hiphotos.baidu.com/image/h%3D360/sign=04ef437b0b23dd543e73a16ee108b3df/50da81cb39dbb6fd9d9ada390b24ab18962b37ef.jpg", 47             "http://b.hiphotos.baidu.com/image/h%3D360/sign=e91921f7c1fdfc03fa78e5bee43e87a9/8b82b9014a90f60352684b4e3b12b31bb151eddb.jpg", 48             "http://g.hiphotos.baidu.com/image/h%3D360/sign=a2540bdbf21f3a2945c8d3c8a925bce3/fd039245d688d43fa9943bf77f1ed21b0ef43bf1.jpg", 49             "http://p4.so.qhimg.com/bdr/_240_/t01d4c378e7c6bfbe69.jpg", 50             "http://p0.so.qhimg.com/bdr/_240_/t0160872a7d33df5735.jpg", 51             "http://p3.so.qhimg.com/bdr/_240_/t01473a131702c357dd.jpg" }; 52  53     @Override 54     protected void onCreate(Bundle savedInstanceState) { 55         super.onCreate(savedInstanceState); 56         setContentView(R.layout.activity_main); 57  58         activity = this; 59  60         data = new ArrayList<HashMap<String, Object>>(); 61         cache = new ArrayList<HashMap<String, Object>>(); 62         // 添加初始数据 63         for (int i = 0; i < 30; i++) { 64             HashMap<String, Object> map = new HashMap<String, Object>(); 65             map.put(KEY_IMAGE, BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher)); 66             map.put(KEY_TEXT, i); 67             data.add(map); 68         } 69  70         lv = (MyRefreshListview) findViewById(R.id.listview); 71  72         mMyAdapter = new MyAdapter(this, -1); 73  74         lv.setAdapter(mMyAdapter); 75  76         lv.setOnRefreshListener(new OnRefreshListener() { 77  78             @Override 79             public void ontop() { 80                 // 随机加入一张图片 81                 adddata(image_urls[random.nextInt(8)]); 82  83             } 84  85             @Override 86             public void onbuttom() { 87                 // 没有设置缓存机制 88                 new MyAsyncTaskBottom(image_urls[random.nextInt(8)]).execute(); 89             } 90         }); 91     } 92  93     private class MyAdapter extends ArrayAdapter<String> { 94         private LayoutInflater flater; 95         private Context context; 96  97         public MyAdapter(Context context, int resource) { 98  99             super(context, resource);100             this.context = context;101             flater = LayoutInflater.from(context);102 103         }104 105         @Override106         public int getCount() {107             return data.size();108         }109 110         @SuppressLint("InflateParams")111         @Override112         public View getView(int position, View convertView, ViewGroup parent) {113 114             if (convertView == null)115                 convertView = flater.inflate(R.layout.list, null);116 117             ImageView iv = (ImageView) convertView.findViewById(R.id.image);118 119             iv.setImageBitmap((Bitmap) data.get(position).get(KEY_IMAGE));120 121             TextView tv = (TextView) convertView.findViewById(R.id.text);122 123             tv.setText(position + "原始数据");124 125             return convertView;126         }127 128     }129 130     private class MyAsyncTaskTop extends AsyncTask {131         private ProgressDialog pd;132         @SuppressWarnings("unused")133         private String url;134 135         public MyAsyncTaskTop(String url) {136             this.url = url;137         }138 139         @Override140         protected void onPreExecute() {141             // 设置加载进度条142             pd = new ProgressDialog(activity);143             pd.setProgressStyle(pd.STYLE_HORIZONTAL);144             pd.setMessage("正在加载。。。");145             pd.show();146         }147 148         @Override149         protected Object doInBackground(Object... params) {150 151             try {152                 // 回调加载网络的类Loadnetimage153                 Loadnetimage mLoadnetimage = new Loadnetimage();154 155                 mLoadnetimage.SetLoadnetimageListener(new OnLoadnetimageListener() {156 157                     @SuppressWarnings("unchecked")158                     @Override159                     public void LoadnetimageListener(int count, int total) {160                         publishProgress(count, total);161 162                     }163                 });164                 // 获取网络图片165                 Bitmap bitmap = mLoadnetimage.loadRawDataFromURL(url);166                 // 每次将图片和对应的地址放入HashMap167                 HashMap<String, Object> map = new HashMap<String, Object>();168                 // 将新加载图片放入缓存169                 map.put(CACHE_KEY_IMAGE, bitmap);170                 map.put(CACHE_KEY_TEXT, url);171 172                 cache.add(map);173 174                 return bitmap;175             } catch (Exception e) {176                 e.printStackTrace();177             }178 179             return null;180 181         }182 183         @Override184         protected void onPostExecute(Object result) {185             addtop(result);186             pd.dismiss();187 188         }189 190         // 更新进度条191         @Override192         protected void onProgressUpdate(Object... values) {193             int count = (Integer) values[0];194             int total = (Integer) values[1];195 196             pd.setMax(total);197             pd.setProgress(count);198 199         }200 201     }202 203     @SuppressWarnings("unused")204     private class MyAsyncTaskBottom extends AsyncTask {205         private ProgressDialog pd;206         private String url;207 208         public MyAsyncTaskBottom(String url) {209             this.url = url;210         }211 212         @Override213         protected void onPreExecute() {214             // 设置进度条215             pd = new ProgressDialog(activity);216             // 样式217             pd.setProgressStyle(pd.STYLE_HORIZONTAL);218             pd.setMessage("正在加载。。。");219             pd.show();220 221         }222 223         @Override224         protected Object doInBackground(Object... params) {225             // 回调加载网络的类Loadnetimage226             Loadnetimage mLoadnetimage = new Loadnetimage();227             // 获取网络图片228             Bitmap bitmap;229             try {230                 bitmap = mLoadnetimage.loadRawDataFromURL(url);231                 return bitmap;232             } catch (Exception e) {233                 e.printStackTrace();234             }235             return null;236         }237 238         @Override239         protected void onPostExecute(Object result) {240             addbottom(result);241             pd.dismiss();242 243         }244 245     }246 247     private void adddata(String url) {248         // 设置缓存机制249         Log.e("", "开始添加");250 251         for (int i = 0; i < cache.size(); i++) {252 253             HashMap<String, Object> map = cache.get(i);254             // 判断图片地址一样则载入缓存255             if (url.equals(map.get(CACHE_KEY_TEXT))) {256                 Bitmap bitmap = (Bitmap) map.get(CACHE_KEY_IMAGE);257                 addtop(bitmap);258                 Log.e("", "载入缓存");259 260                 return;261             }262 263         }264         // 否则从网络新加载265         Log.e("", "最新加载");266         new MyAsyncTaskTop(url).execute();267 268     }269 270     private void addtop(Object result) {271 272         // 新加载图片放入原始数据273         HashMap<String, Object> map = new HashMap<String, Object>();274         map.put(KEY_IMAGE, result);275         map.put(KEY_TEXT, data.size() + 1);276 277         data.add(0, map);278 279         mMyAdapter.notifyDataSetChanged();280     }281 282     private void addbottom(Object result) {283         HashMap<String, Object> map = new HashMap<String, Object>();284         map.put(KEY_IMAGE, result);285         map.put(KEY_TEXT, data.size() + 1);286 287         data.add(map);288 289         mMyAdapter.notifyDataSetChanged();290         // 添加数据后自动滚动到底部291         lv.setSelection(ListView.FOCUS_DOWN);292 293     }294 295 }

 1 package com.lixu.listviewrefresh; 2  3 import java.io.BufferedInputStream; 4 import java.io.ByteArrayOutputStream; 5 import java.io.InputStream; 6 import java.net.HttpURLConnection; 7 import java.net.URL; 8  9 import android.graphics.Bitmap;10 import android.graphics.BitmapFactory;11 12 public class Loadnetimage {13     // 设置回调机制14     15     private OnLoadnetimageListener mOnLoadnetimageListener;16 17     public Loadnetimage() {18 19     }20 21     public interface OnLoadnetimageListener {22         public void LoadnetimageListener(int count, int total);23     }24 25     public void SetLoadnetimageListener(OnLoadnetimageListener l) {26         mOnLoadnetimageListener = l;27     }28     29     30 31     public Bitmap loadRawDataFromURL(String u) throws Exception {32         33         URL url = new URL(u);34         HttpURLConnection conn = (HttpURLConnection) url.openConnection();35         // 设置请求的一些常用的参数36         conn.setReadTimeout(30000);37         conn.setConnectTimeout(30000);38         conn.setDoInput(true);39         conn.connect();40         // 获取图片总数41         int total = conn.getContentLength();42 43         InputStream is = conn.getInputStream();44         BufferedInputStream bis = new BufferedInputStream(is);45 46         ByteArrayOutputStream baos = new ByteArrayOutputStream();47         // 缓存2KB48         final int BUFFER_SIZE = 2 * 1024;49         final int EOF = -1;50 51         int count = 0;52 53         int c;54         byte[] buf = new byte[BUFFER_SIZE];55 56         while (true) {57             c = bis.read(buf);58             if (c == EOF)59                 break;60             // 每次累加到现在为止我们下载了多少数据，以便于后面计算已经下载的数据占了总数量的百分比61             count = count + c;62             // 发布最新的数据，更新随后的进度条显示进度使用63             if (mOnLoadnetimageListener != null)64                 mOnLoadnetimageListener.LoadnetimageListener(count, total);65             baos.write(buf, 0, c);66         }67 68         conn.disconnect();69         is.close();70 71         byte[] data = baos.toByteArray();72         baos.flush();73 74         Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);75 76         return bitmap;77     }78 79 }

 1 package com.lixu.listviewrefresh; 2  3 import android.content.Context; 4 import android.util.AttributeSet; 5 import android.view.GestureDetector; 6 import android.view.MotionEvent; 7 import android.view.View; 8 import android.widget.AbsListView; 9 import android.widget.ListView;10 11 public class MyRefreshListview extends ListView {12     private OnRefreshListener mOnRefreshListener;13     private Context context;14     private int firstVisibleItem, visibleItemCount, totalItemCount;15 16     public MyRefreshListview(Context context, AttributeSet attrs) {17         super(context, attrs);18         this.context = context;19 20     }21 22     public interface OnRefreshListener {23 24         public void ontop();25 26         public void onbuttom();27     }28 29     public void setOnRefreshListener(OnRefreshListener l) {30         this.mOnRefreshListener = l;31         // 这个方法可以解决当listview中初始没有数据的时候滑动来加载数据32         final GestureDetector mGestureDetector = new GestureDetector(context,33                 new GestureDetector.SimpleOnGestureListener() {34 35                     // velocityY表示触摸停止点Y到触摸起始点Y的速度值 当两点距离值为负时，速度值也为负所以：36                     // >0表示从上往下拉37                     // <0表示从下往上拉38                     public boolean onFling(android.view.MotionEvent e1, android.view.MotionEvent e2, float velocityX,39                             float velocityY) {40                         if (velocityY > 0) {41 42                             // 滑动到顶部时添加43                             if (firstVisibleItem == 0) {44 45                                 mOnRefreshListener.ontop();46 47                             }48 49                         }50                         if (velocityY < 0) {51                             // 滑动到底部时添加52                             if ((firstVisibleItem + visibleItemCount) == totalItemCount) {53 54                                 mOnRefreshListener.onbuttom();55 56                             }57                         }58 59                         return super.onFling(e1, e2, velocityX, velocityY);60                     };61 62                 });63         this.setOnTouchListener(new OnTouchListener() {64             // 将触摸事件交给GestureDetector来处理65             @Override66             public boolean onTouch(View v, MotionEvent event) {67 68                 return mGestureDetector.onTouchEvent(event);69             }70         });71 72         this.setOnScrollListener(new OnScrollListener() {73 74             @Override75             public void onScrollStateChanged(AbsListView view, int scrollState) {76 77             }78 79             @Override80             public void onScroll(AbsListView view, int fvi, int vic, int tic) {81 82                 firstVisibleItem = fvi;83                 visibleItemCount = vic;84                 totalItemCount = tic;85 86             }87         });88 89     }90 91 }

 

xml文件：

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 2     xmlns:tools="http://schemas.android.com/tools" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent" 5     tools:context="com.lixu.listviewrefresh.MainActivity" > 6  7     <com.lixu.listviewrefresh.MyRefreshListview 8         android:id="@+id/listview" 9         android:layout_width="match_parent"10         android:layout_height="match_parent" />11 12 </RelativeLayout>

 1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent" 5     android:orientation="vertical" > 6  7     <ImageView 8         android:id="@+id/image" 9         android:layout_width="match_parent"10         android:layout_height="match_parent" />11 12     <TextView13         android:id="@+id/text"14         android:layout_width="match_parent"15         android:layout_height="match_parent" />16 17 </LinearLayout>

运行效果图：