Question

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        HttpClient httpclient = new DefaultHttpClient();
        HttpGet httpget = new HttpGet("http://domain.com");
        try {
            HttpResponse response = httpclient.execute(httpget);
            if(response != null) {
                String line = "";
                InputStream inputstream = response.getEntity().getContent();
                line = convertStreamToString(inputstream);
                Toast.makeText(getActivity(), line, Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(getActivity(), "Unable to complete your request", Toast.LENGTH_LONG).show();
            }
        } catch (ClientProtocolException e) {
            Toast.makeText(getActivity(), "Caught ClientProtocolException", Toast.LENGTH_SHORT).show();
        } catch (IOException e) {
            Toast.makeText(getActivity(), "Caught IOException", Toast.LENGTH_SHORT).show();
        } catch (Exception e) {
            Toast.makeText(getActivity(), "Caught Exception", Toast.LENGTH_SHORT).show();
        }
        //Log.i("DATA FROM MYSQL", output);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(inflater.getContext(), android.R.layout.simple_list_item_1,countries);
        setListAdapter(adapter);
        return super.onCreateView(inflater, container, savedInstanceState);
    }
    private static String convertStreamToString(InputStream is) {
        /*
         * To convert the InputStream to String we use the BufferedReader.readLine()
         * method. We iterate until the BufferedReader return null which means
         * there's no more data to read. Each line will appended to a StringBuilder
         * and returned as String.
         */
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }

每次我得到＆＃34;抓住异常＆＃34;输出，什么错？

Answer 1

我敢打赌，你得到的例外是NetworkingOnMainThreadException。网络操作往往需要一些时间，这就是为什么禁止在Android的主（ui）线程上执行此类操作的原因。这会使UI无响应，从而导致非常糟糕的用户体验。

查看AsyncTask以便将操作优雅地移动到后台线程。

一直抓到异常

1 个答案: