圖片非同步下載載入代碼

 1 import java.io.IOException; 2 import java.io.InputStream; 3 import java.util.HashMap; 4 import java.util.Map; 5  6 import org.apache.http.HttpResponse; 7 import org.apache.http.client.ClientProtocolException; 8 import org.apache.http.client.methods.HttpGet; 9 import org.apache.http.impl.client.DefaultHttpClient;10 11 import android.graphics.drawable.Drawable;12 import android.os.Handler;13 import android.os.Message;14 import android.widget.ImageView;15 16 public class DrawableManager {17 18     private final Map<String, Drawable> drawableMap;19 20     public DrawableManager() {21         drawableMap = new HashMap<String, Drawable>();22     }23 24     public Drawable fatchDrawable(String urlString) {25         if (drawableMap.containsKey(urlString)) {26             return drawableMap.get(urlString);27         }28         try {29             InputStream is = fetch(urlString);30             Drawable drawable = Drawable.createFromStream(is, "src");31             drawableMap.put(urlString, drawable);32             return drawable;33         } catch (ClientProtocolException e) {34             // TODO Auto-generated catch block35             e.printStackTrace();36             return null;37         } catch (IOException e) {38             // TODO Auto-generated catch block39             e.printStackTrace();40             return null;41         }42 43     }44 45     public void fetchDrawableOnThread(final String urlString,46             final ImageView imageView) {47         if (drawableMap.containsKey(urlString)) {48             imageView.setImageDrawable(drawableMap.get(urlString));49         }50         final Handler handler = new Handler() {51 52             @Override53             public void handleMessage(Message msg) {54                 // TODO Auto-generated method stub55                 imageView.setImageDrawable((Drawable) msg.obj);56             }57         };58 59         Thread thread = new Thread() {60 61             @Override62             public void run() {63                 // TODO Auto-generated method stub64                 Drawable drawable = fatchDrawable(urlString);65                 Message msg = handler.obtainMessage(1, drawable);66                 handler.sendMessage(msg);67             }68         };69         thread.start();70     }71 72     private InputStream fetch(String urlString) throws ClientProtocolException,73             IOException {74         DefaultHttpClient httpClient = new DefaultHttpClient();75         HttpGet request = new HttpGet(urlString);76         HttpResponse response = httpClient.execute(request);77         return response.getEntity().getContent();78 79     }80 }