new MyAsyncTask()
					.execute("http://pic.baike.soso.com/p/20120716/bki-20120716095331-640956396.jpg");
class MyAsyncTask extends AsyncTask<String, Void, Bitmap> {
		@Override
		protected void onPreExecute() {
			// TODO 自动生成的方法存根
			super.onPreExecute();
			dialog.show();
}
		@Override
		protected Bitmap doInBackground(String... params) {
			Bitmap bitmap = null;
			HttpClient httpClient = new DefaultHttpClient();
			HttpGet httpPost = new HttpGet(params[0]);
			try {
				HttpResponse respon = httpClient.execute(httpPost);
			
				if (respon.getStatusLine().getStatusCode() == 200) {
					HttpEntity entity = respon.getEntity();
					byte[] data = EntityUtils.toByteArray(entity);
					bitmap = BitmapFactory
							.decodeByteArray(data, 0, data.length);
				}
				else {
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
			return bitmap;
		}
		@Override
		protected void onPostExecute(Bitmap result) {
			// TODO 自动生成的方法存根
			super.onPostExecute(result);
			imageView.setImageBitmap(result);
			dialog.dismiss();
			
		}
}
原文:http://www.cnblogs.com/lzh-Linux/p/4584095.html