android下面圖片更新是需要啓動多個子線程來進行的，而android下面是並不是線程安全的，所以thread這裏是用不了的，只能用runnable接口。
廢話不多說了 直接上代碼。
1、下載線程 繼承runnable接口
public class DownloadImage implements Runnable {
private ImageView p_w_picpathView;
private String p_w_picpathUrl;
private Bitmap bitmap;
//構造的時候傳入要更新的ImageView ，同時傳入圖片的URL
public DownloadImage(ImageView p_w_picpathView, String p_w_picpathUrl) {
super();
this.p_w_picpathView = p_w_picpathView;
this.p_w_picpathUrl = p_w_picpathUrl;
}
public Handler handler = new Handler();
Runnable updateResults = new Runnable() {
@Override
public void run() {
updateUI();
}
};
public void run() {
HttpGet httpRequest = null;
URL url;
try {
url = new URL(p_w_picpathUrl);
httpRequest = new HttpGet(url.toURI());
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity);
InputStream instream = bufHttpEntity.getContent();
bitmap = BitmapFactory.decodeStream(instream);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
handler.post(updateResults);
}
public void updateUI(){
p_w_picpathView.setImageBitmap(bitmap);
}
}
2、主程序
ImageView p_w_picpathView = (ImageView)findViewById(R.id.p_w_picpath);
String p_w_picpathUrl = "http://www.qqzhi.com/show/UploadPic/2010-5/2010521102357899.jpg";
new Thread(new DownloadImage(p_w_picpathView, p_w_picpathUrl)).start();
這些添加在oncreate（）裏面就實現了圖片的更新了
3、配置文件AndroidManifest
<uses-permission android:name="android.permission.INTERNET"/>
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4、佈局文件
<ImageView
android:id="@+id/p_w_picpath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x = "100px"
android:layout_y = "100px"
android:src="@drawable/icon"
/>
OK，要實現的功能就完全實現了，你可以定義N個變量（就是你需要更新的圖片），目前我測試一次更新20幅消耗時間1s。
希望能對大家有所幫助，有興趣可以一起討論！