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 @Override
106 public int getCount() {
107 return data.size();
108 }
109
110 @SuppressLint("InflateParams")
111 @Override
112 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 @Override
140 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 @Override
149 protected Object doInBackground(Object... params) {
150
151 try {
152 // 回调加载网络的类Loadnetimage
153 Loadnetimage mLoadnetimage = new Loadnetimage();
154
155 mLoadnetimage.SetLoadnetimageListener(new OnLoadnetimageListener() {
156
157 @SuppressWarnings("unchecked")
158 @Override
159 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HashMap
167 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 @Override
184 protected void onPostExecute(Object result) {
185 addtop(result);
186 pd.dismiss();
187
188 }
189
190 // 更新进度条
191 @Override
192 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 @Override
213 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 @Override
224 protected Object doInBackground(Object... params) {
225 // 回调加载网络的类Loadnetimage
226 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 @Override
239 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2KB
48 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.widget.AbsListView;
6 import android.widget.ListView;
7
8 public class MyRefreshListview extends ListView {
9 private OnRefreshListener mOnRefreshListener;
10
11 public MyRefreshListview(Context context, AttributeSet attrs) {
12
13 super(context, attrs);
14
15 }
16
17 public interface OnRefreshListener {
18
19 public void ontop();
20
21 public void onbuttom();
22 }
23
24 public void setOnRefreshListener(OnRefreshListener l) {
25 this.mOnRefreshListener = l;
26
27 this.setOnScrollListener(new OnScrollListener() {
28
29 private int firstVisibleItem, visibleItemCount, totalItemCount;
30
31 @Override
32 public void onScrollStateChanged(AbsListView view, int scrollState) {
33
34 // 当滑动停止的时候判断
35 if (OnScrollListener.SCROLL_STATE_IDLE == scrollState) {
36 // 滑动到顶部时添加
37 if (firstVisibleItem == 0) {
38
39 mOnRefreshListener.ontop();
40
41 }
42 // 滑动到底部时添加
43 else if ((firstVisibleItem + visibleItemCount) == totalItemCount) {
44
45 mOnRefreshListener.onbuttom();
46
47 }
48 }
49
50 }
51
52 @Override
53 public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
54
55 this.firstVisibleItem = firstVisibleItem;
56 this.visibleItemCount = visibleItemCount;
57 this.totalItemCount = totalItemCount;
58
59 }
60 });
61
62 }
63 }
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 <TextView 13 android:id="@+id/text" 14 android:layout_width="match_parent" 15 android:layout_height="match_parent" /> 16 17 </LinearLayout>
运行效果图：
时间： 2024-10-04 11:47:10