AsyncTask

		@Override
		protected void onPostExecute(String result) {
			Gson gson = new Gson();
			Bean bean = gson.fromJson(json, Bean.class);
			list = bean.data.list;
			list2.addAll(list);
			lv.setAdapter(new Adapter(list2, MainActivity.this));
			pro.setVisibility(View.GONE);
			// progressDialog.dismiss();
			super.onPostExecute(result);
		}

		@Override
		protected void onPreExecute() {
			pro.setVisibility(View.VISIBLE);
			/*
			 * progressDialog = new ProgressDialog(MainActivity.this);
			 * progressDialog.setTitle("人家正在努力加载");
			 * progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
			 * progressDialog.show();
			 */
			super.onPreExecute();
		}

 网络请求工具类： public class Util extends AsyncTask<String, Void, String>{ private String json; @Override protected String doInBackground(String... params) { try { URL url=new URL(params[0]); HttpURLConnection connection=(HttpURLConnection) url.openConnection(); if(connection.getResponseCode()==200){ InputStream is = connection.getInputStream(); byte[] by=new byte[1024]; int len; ByteArrayOutputStream os=new ByteArrayOutputStream(); while((len=is.read(by))!=-1){ os.write(by, 0, len); } json = os.toString("gbk"); return json; } } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } }