Question

当我执行这个异步任务时，我得到一个networkOnmainThreadException：

class GetGroupBiography extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(BiographyActivity.this);
        pDialog.setMessage("Loading biography details. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    /**
     * Getting product details in background thread
     * */
    protected String doInBackground(String... params) {

        // updating UI from Background Thread
        runOnUiThread(new Runnable() {
            public void run() {
                // Check for success tag
                int success;
                try {
                    // Building Parameters
                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    params.add(new BasicNameValuePair("nombre_grupo", nombre_grupo));

                    // getting product details by making HTTP request
                    // Note that product details url will use GET request
                    JSONObject json = jsonParser.makeHttpRequest(get_biography_url, "GET", params);

                    // check your log for json response
                    Log.d("Biography Details", json.toString());

                    // json success tag
                    success = json.getInt(TAG_SUCCESS);
                    if (success == 1) {
                        // successfully received product details
                        JSONArray groupObj = json
                                .getJSONArray(TAG_GROUP); // JSON Array

                        // get first product object from JSON Array
                        JSONObject group = groupObj.getJSONObject(0);

                        // product with this pid found
                        // Edit Text
                        textName = (EditText) findViewById(R.id.textName);
                        textAnyo = (EditText) findViewById(R.id.textDate);
                        textDescripcion = (EditText) findViewById(R.id.textDescription);

                        // display product data in EditText
                        textName.setText(group.getString(TAG_NAME));
                        textAnyo.setText(group.getString(TAG_ANYO));
                        textDescripcion.setText(group.getString(TAG_DESCRIPTION));

                    }else{
                        // product with pid not found
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        });

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String result) {
        // dismiss the dialog once got all details
        super.onPostExecute(result);

        if (pDialog.isShowing()) {
            pDialog.dismiss();
            // progressDialog.setCancelable(true);
        }
    }
}

我从此代码部分调用此异步任务：

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_biography);
    AlertDialog.Builder ald = new AlertDialog.Builder(BiographyActivity.this);
    ald.setTitle("Nombre del grupo");
    ald.setMessage("Introduce el nombre del grupo:");
    final EditText texto = new EditText(BiographyActivity.this);
    ald.setView(texto);
    ald.setPositiveButton("Aceptar", new DialogInterface.OnClickListener() {


        @Override
        public void onClick(DialogInterface dialog, int which) {
            // TODO Auto-generated method stub
            nombre_grupo = texto.getText().toString();
            new GetGroupBiography().execute();
        }
    });
    ald.show();

}

我必须做些什么来避免这种异常。因为我试图将json移动到onpostexecute（）但它没有用。我希望能帮助你完成这项任务，因为我必须尽快完成这项任务。

Answer 1

我必须采取哪些措施来避免此异常

摆脱runOnUiThread()。

然后，在doInBackground()中执行JSON解析，并将UI更新逻辑（例如，setText()调用）移至onPostExecute()。

Answer 2

您无法在UI线程上执行网络操作，然后明确要求UI线程执行这些操作

删除runOnuiThread并将其保留在DoInBackground。

把它放在postexecute上：

                    textName = (EditText) findViewById(R.id.textName);
                    textAnyo = (EditText) findViewById(R.id.textDate);
                    textDescripcion = (EditText) findViewById(R.id.textDescription);

                    // display product data in EditText
                    textName.setText(group.getString(TAG_NAME));
                    textAnyo.setText(group.getString(TAG_ANYO));
                    textDescripcion.setText(group.getString(TAG_DESCRIPTION));

执行异步任务时出现android.os.NetworkOnMainThreadException错误

2 个答案: