获取网络图片并异步更新UI

private Button button;
	private ImageView imageView;
	private String image_path = "http://ww1.sinaimg.cn/mw600/a84f073ajw1dvlhrku4ppj.jpg";
	private final int IS_FINISH = 1;
	private ProgressDialog progressDialog = null;
	private Handler handler = new Handler(){
		@Override
		public void handleMessage(android.os.Message msg) {
			byte[] data = (byte[])msg.obj;
			Bitmap bm = BitmapFactory.decodeByteArray(data, 0, data.length);
			imageView.setImageBitmap(bm);
			if (msg.what == IS_FINISH) {
				progressDialog.dismiss();
			}
		};
	};
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		
		progressDialog = new ProgressDialog(this);
		progressDialog.setTitle("提示");
		progressDialog.setMessage("正在下载，请稍后");
		progressDialog.setCancelable(false);
		button = (Button) this.findViewById(R.id.button1);
		imageView = (ImageView) this.findViewById(R.id.imageview1);
		button.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				new Thread(new MyThread()).start();
				progressDialog.show();
			}
		});
	}
	
	public class MyThread implements Runnable{

		@Override
		public void run() {
			HttpClient httpClient = new DefaultHttpClient();
			HttpGet httpGet = new HttpGet(image_path);
			HttpResponse httpResponse = null;
			try {
				httpResponse = httpClient.execute(httpGet);
				if (httpResponse.getStatusLine().getStatusCode() == 200) {
					byte[] data = EntityUtils.toByteArray(httpResponse.getEntity());
					Message message = Message.obtain();
					message.obj = data;
					message.what = IS_FINISH;
					handler.sendMessage(message);
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		
	}

线程中执行耗时操作，handler中异步更新UI。网络获取图片、传递byte数组及byte数组转化为bitmap