android - AsyncTask 不适用于 4.0.4

Question

我在下面创建了一个类，它连接到互联网并向 php 脚本发送请求。为了在 4.0.4 上工作，我像 AsyncTask 一样创建了它，而不是在主线程中创建它，但是当我测试它时，它不起作用，尽管它在 2.2 上工作正常。你知道问题出在哪里吗？

class download extends AsyncTask<String, Integer, String> {

        protected String doInBackground(String s1, String s2) {
            String result = "";
            //http post

            ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
            nameValuePairs.add(new BasicNameValuePair("Vreme", s1));
            nameValuePairs.add(new BasicNameValuePair("Datum", s2));

            InputStream is = null;
            try {

                String adresa = "http://senzori.open.telekom.rs/script.php";
                HttpPost httppost = new HttpPost(adresa);
                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                HttpClient httpclient = new DefaultHttpClient();

                HttpResponse response = httpclient.execute(httppost);
                HttpEntity entity = response.getEntity();
                is = entity.getContent();
            } catch (Exception e) {
                Log.e("log_tag", "Error in http connection " + e.toString());
            }
            //convert response to string
            try {
                BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
                StringBuilder sb = new StringBuilder();
                String line = null;
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
                is.close();

                result = sb.toString();

            } catch (Exception e) {
                Log.e("log_tag", "Error converting result " + e.toString());
            }
            return result;
        }

        @Override
        protected String doInBackground(String... params) {
            // TODO Auto-generated method stub
            return null;
        }
    }

Answer 1

它可能不工作，因为你重载了 doInBackground，但没有调用重载的方法。

改成原来的方法是这样的:

@Override
protected String doInBackground(String... params) {

    return doInBackground (params[0], params[1]);
}

请注意，它现在使重载无用，将代码移回覆盖的 doInBackground (String... params)，并且您还需要确保在调用 execute 时()，您提供两个字符串作为参数。