Android 多线程处理之多线程用法大集合 第 4 页

第 4 页 全部源码

 1 package com.bvin.exec;
  2 
  3 import java.io.IOException;
  4 import java.net.MalformedURLException;
  5 import java.net.URL;
  6 import java.util.concurrent.ExecutorService;
  7 import java.util.concurrent.Executors;
  8 
  9 import android.app.Activity;
10 import android.graphics.drawable.Drawable;
11 import android.os.AsyncTask;
12 import android.os.Bundle;
13 import android.os.Handler;
14 import android.os.HandlerThread;
15 import android.os.Message;
16 import android.util.Log;
17 import android.view.View;
18 import android.widget.Button;
19 import android.widget.ImageView;
20 
21 public class MainActivity extends Activity {
22     /** Called when the activity is first created. */
23     
24     private Handler handler ;
25     private Button bt;
26     private Handler mainHandler = new Handler(){
27 
28         @Override
29         public void handleMessage(Message msg) {
30             // TODO Auto-generated method stub
31             super.handleMessage(msg);
32             if(msg.what == 2012){
33                 //只要在主线程就可以处理ui 
34                 ((ImageView)MainActivity.this.findViewById(msg.arg1)).setImageDrawable((Drawable)msg.obj);
35             }
36         }
37         
38         
39     };
40     
41     private ExecutorService service = Executors.newFixedThreadPool(5);
42     
43     @Override
44     public void onCreate(Bundle savedInstanceState) {
45         super.onCreate(savedInstanceState);
46         setContentView(R.layout.main);
47         initViews();
48         HandlerThread ht = new HandlerThread("down image thread");
49         ht.start();
50         handler = new Handler(ht.getLooper()){//如果有了looper那么这个handler就不可以处理ui了
51 
52             @Override
53             public void handleMessage(Message msg) {
54                 // TODO Auto-generated method stub
55                 super.handleMessage(msg);
56                 
57                 
58             }
59             
60         };
61         
62     }
63     
64     private void initViews(){
65         
66         bt = (Button)findViewById(R.id.bt);
67         bt.setOnClickListener(new View.OnClickListener() {
68             
69             @Override
70             public void onClick(View v) {
71                 // TODO Auto-generated method stub
72                 loadImagesByExecutors("http://news.baidu.com/z/resource/r/image/2012-11-23/23c1625aca99f02c50d8e510383a34e7.jpg",R.id.iv1);
73                 loadImagesByExecutors("http://news.baidu.com/z/resource/r/image/2012-11-23/c4698d97ef6d10722c8e917733c7beb3.jpg",R.id.iv2);
74                 loadImagesByExecutors("http://news.baidu.com/z/resource/r/image/2012-11-23/f332ffe433be2a3112be15f78bff5a40.jpg",R.id.iv3);
75                 loadImagesByExecutors("http://news.baidu.com/z/resource/r/image/2012-11-23/6ff8a9c647a1e80bc602eeda48865d4c.jpg",R.id.iv4);
76                 loadImagesByExecutors("http://news.baidu.com/z/resource/r/image/2012-11-23/f104d069f7443dca52a878d779392874.jpg",R.id.iv5);
77             }
78         });
79     }
80     
81     private void loadImagesByHandler(final String url,final int id){//通过拥有looper的handler.post(runnable)，新建线程
82         
83         
84         handler.post(new Runnable(){//如果handler没有Looper那么它就不能构建新线程了
85 
86             @Override
87             public void run() {
88                 // TODO Auto-generated method stub
89                 Log.e("当前线程：", ""+Thread.currentThread().getName());
90                 Drawable drawable = null;
91                 try {
92                     drawable = Drawable.createFromStream(new URL(url).openStream(), "image.gif");
93                 } catch (MalformedURLException e) {
94                     // TODO Auto-generated catch block
95                     e.printStackTrace();
96                 } catch (IOException e) {
97                     // TODO Auto-generated catch block
98                     e.printStackTrace();
99                 }
100                 //SystemClock.sleep(2000);
101                 //((ImageView)MainActivity.this.findViewById(id)).setImageDrawable(drawable);
102                 Message msg = mainHandler.obtainMessage();
103                 msg.what = 2012;
104                 msg.arg1 = id;
105                 msg.obj = drawable;
106                 msg.sendToTarget();
107             }
108             
109         });
110         
111         
112     }
113     
114     private void loadImagesByThread(final String url,final int id){//通过Thread来new 出多个线程
115         
116         new Thread(new Runnable(){
117 
118             @Override
119             public void run() {
120                 // TODO Auto-generated method stub
121                 Log.e("当前线程：", ""+Thread.currentThread().getName());
122                 Drawable drawable = null;
123                 try {
124                     drawable = Drawable.createFromStream(new URL(url).openStream(), "image.gif");
125                 } catch (MalformedURLException e) {
126                     // TODO Auto-generated catch block
127                     e.printStackTrace();
128                 } catch (IOException e) {
129                     // TODO Auto-generated catch block
130                     e.printStackTrace();
131                 }
132                 Message msg = mainHandler.obtainMessage();
133                 msg.what = 2012;
134                 msg.arg1 = id;
135                 msg.obj = drawable;
136                 msg.sendToTarget();
137                 
138             }
139             
140         }).start();
141     } 
142 
143     private void loadImageByAsyncTask(final String url,final int id){//构建异步任务，这样就不用handler来处理消息了
144         DownloadTask task = new DownloadTask();
145         task.execute(""+id,url);//AsyncTask不可重复执行
146     }
147     
148     private void loadImagesByExecutors(final String url,final int id){
149         service.submit(new Runnable(){
150             
151             @Override
152             public void run() {
153                 // TODO Auto-generated method stub
154                 Log.e("当前线程：", ""+Thread.currentThread().getName());
155                 
156                 try {
157                     final Drawable drawable  = Drawable.createFromStream(new URL(url).openStream(), "image.gif");
158                     mainHandler.post(new Runnable(){
159 
160                         @Override
161                         public void run() {//这将在主线程运行
162                             // TODO Auto-generated method stub
163                             ((ImageView)MainActivity.this.findViewById(id)).setImageDrawable(drawable);
164                         }
165                     });
166                     
167                 } catch (MalformedURLException e) {
168                     // TODO Auto-generated catch block
169                     e.printStackTrace();
170                 } catch (IOException e) {
171                     // TODO Auto-generated catch block
172                     e.printStackTrace();
173                 }
174                 
175             }
176             
177         });
178         
179     }
180     
181     class DownloadTask extends AsyncTask{
182 
183         int id;
184         @Override
185         protected Drawable doInBackground(String... params) {//params保存url和控件id两个数据
186             // TODO Auto-generated method stub
187             Log.e("当前线程：", ""+Thread.currentThread().getName());
188             Drawable drawable = null;
189             this.id = Integer.parseInt(params[0]);
190             try {
191                 drawable = Drawable.createFromStream(new URL(params[1]).openStream(), "image.gif");
192             } catch (MalformedURLException e) {
193                 // TODO Auto-generated catch block
194                 e.printStackTrace();
195             } catch (IOException e) {
196                 // TODO Auto-generated catch block
197                 e.printStackTrace();
198             }
199             
200             return drawable;
201         }
202 
203         @Override
204         protected void onPostExecute(Drawable result) {
205             // TODO Auto-generated method stub
206             super.onPostExecute(result);
207             ((ImageView)MainActivity.this.findViewById(id)).setImageDrawable(result);
208         }
209 
210         @Override
211         protected void onPreExecute() {
212             // TODO Auto-generated method stub
213             super.onPreExecute();
214         }
215 
216         @Override
217         protected void onProgressUpdate(Integer... values) {
218             // TODO Auto-generated method stub
219             super.onProgressUpdate(values);
220         }
221 
222         
223     }
224 }