I'm creating a AsyncTask to login user to a server.
The login works fine, but the ProgressDialog does not show until the end of the process.
As soon as the user taps the button, the UI freezes, and my dialog does not show up.
I appreciate any help. Here's my code.
public class MyApp extends Activity {
private ProgressDialog dialogo = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button loginButton = (Button) findViewById(R.id.btnLogin);
loginButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
SharedPreferences preferencias = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
String webAddress = preferencias.getString("webAddress", "");
if (webAddress.isEmpty()) {
Toast.makeText(getBaseContext(), "Please, configure a Web Address.", Toast.LENGTH_LONG).show();
} else {
EditText edtUsername = (EditText) findViewById(R.id.edtUsername);
EditText edtPassword = (EditText) findViewById(R.id.edtPassword);
HashMap<String, String> parametros = new HashMap<String, String>();
parametros.put("username", edtUsername.getText().toString());
parametros.put("password", edtPassword.getText().toString());
Requisicao requisicao = new Requisicao(parametros);
AsyncTask<String, Void, String> resposta = requisicao.execute(webAddress + "/login");
try {
Toast.makeText(getBaseContext(), resposta.get(), Toast.LENGTH_LONG).show();
} catch (InterruptedException e) {
Toast.makeText(getBaseContext(), "InterruptedException (login)", Toast.LENGTH_LONG).show();
} catch (ExecutionException e) {
Toast.makeText(getBaseContext(), "ExecutionException (login)", Toast.LENGTH_LONG).show();
}
}
}
});
ImageView engrenagem = (ImageView) findViewById(R.id.imgEngrenagem);
engrenagem.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent preferenciasActivity = new Intent(getBaseContext(), Preferencias.class);
startActivity(preferenciasActivity);
}
});
}
public class Requisicao extends AsyncTask<String, Void, String> {
private final HttpClient clienteHttp = new DefaultHttpClient();
private String resposta;
private HashMap<String, String> parametros = null;
public Requisicao(HashMap<String, String> params) {
parametros = params;
}
#Override
protected void onPreExecute() {
dialogo = new ProgressDialog(MyApp.this);
dialogo.setMessage("Aguarde...");
dialogo.setTitle("Comunicando com o servidor");
dialogo.setIndeterminate(true);
dialogo.setCancelable(false);
dialogo.show();
}
#Override
protected String doInBackground(String... urls) {
byte[] resultado = null;
HttpPost post = new HttpPost(urls[0]);
try {
ArrayList<NameValuePair> paresNomeValor = new ArrayList<NameValuePair>();
Iterator<String> iterator = parametros.keySet().iterator();
while (iterator.hasNext()) {
String chave = iterator.next();
paresNomeValor.add(new BasicNameValuePair(chave, parametros.get(chave)));
}
post.setEntity(new UrlEncodedFormEntity(paresNomeValor, "UTF-8"));
HttpResponse respostaRequisicao = clienteHttp.execute(post);
StatusLine statusRequisicao = respostaRequisicao.getStatusLine();
if (statusRequisicao.getStatusCode() == HttpURLConnection.HTTP_OK) {
resultado = EntityUtils.toByteArray(respostaRequisicao.getEntity());
resposta = new String(resultado, "UTF-8");
}
} catch (UnsupportedEncodingException e) {
} catch (Exception e) {
}
return resposta;
}
#Override
protected void onPostExecute(String param) {
dialogo.dismiss();
}
}
}
Try to comment out resposta.get() call in the button listener. I guess it just blocks the main UI thread untill the task is finished.
Couple things. First of all, don't make an instance for ASyncClass because you can only ever call it once, as per the android documentation. So execute like this: new Requisicao().execute(webAddress + "/login");
Also, instead of calling requisicao.get(), which will, again according to documentation "Waits if necessary for the computation to complete, and then retrieves its result" (also known as blocking), from within your async class add an override:
protected void onProgressUpdate(Long... progress) {
CallBack(progress[0]); // for example
}
Where CallBack is a function in your UI thread which will handle processing your progress long, or string, or whatever else you want to throw back. Mind you, your ASync class will have to be defined within the UI class instead of separately.
move your
private ProgressDialog dialogo = null;
into the AsyncTask's fields as you did it with HTTPClient because you don't
seem to use it anywhere and
try to create your dialog in the constructor
public Requisicao(HashMap<String, String> params) {
parametros = params;
dialogo = new ProgressDialog(MyApp.this);
}
in postExecute
if (dialogo .isShowing()) {
dialogo .dismiss();
}
hope it helps.
Related
This is my code where I am trying to login where I am using Async task to accomplish the task.
MainActivity extends Activity {
//define controls
EditText txt_uname, txt_pwd;
TextView txt_Error;
Button btnLogin;
String response = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//initalise controls
txt_uname=(EditText)findViewById(R.id.txtUsername);
txt_pwd=(EditText)findViewById(R.id.txtPassword);
btnLogin =(Button)findViewById(R.id.btnLogin);
txt_Error =(TextView)findViewById(R.id.txtError);
btnLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
String uname = txt_uname.getText().toString();
String pwd = txt_pwd.getText().toString();
validateUserTask task = new validateUserTask();
task.execute(new String[]{uname, pwd});
}
}); //close on listener
}// close onCreate
private class validateUserTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("username", params[0] ));
postParameters.add(new BasicNameValuePair("password", params[1] ));
String res = null;
try {
response = CustomHttpClient.executeHttpPost("https://xyz/restapi/login", postParameters);
res=response.toString();
res= res.replaceAll("\\s+","");
}
catch (Exception e) {
txt_Error.setText(e.toString());
}
return res;
}//close doInBackground
#Override
protected void onPostExecute(String result) {
if(result.equals("1")){
//navigate to Main Menu
Intent i = new Intent(MainActivity.this, MainMenuActivity.class);
startActivity(i);
}
else{
txt_Error.setText("Sorry!! Incorrect Username or Password");
}
}
}
}
I am not getting the response from the rest API but it is working fine when I had tested in Postman. Can any one let me know what I am missing and let me know if there are any tutorials for it?
I am trying to create a native login screen, where the username and password boxes slide off the screen while the request is being processed (and slide back up if the login is unsuccessful).
In order to achieve that, I have defined my animation (DropDownAnimation) and I assign it to my LinearLayout (footer). When the user clicks the Login button, I start the animation, and then call a function (tryLogin()) which starts an AsyncTask. The AsyncTask handles all the work of creating and sending the login request, and getting the JSONObject response.
However, my problem is that the slideDown animation doesn't start until after the AsyncTask has completed. This doesn't look so bad on a successful login, but on a failed login it means that the LinearLayout never slides down - it jumps to the bottom of the screen, to begin the slideUp animation back to its original position.
This seems like a similar problem to this question, but I'm not doing using bindService() and all my non-UI code seems (to me) to be contained in the AsyncTask already. LogCat tells me:
06-24 04:37:35.141: I/Choreographer(5347): Skipped 137 frames! The application may be doing too much work on its main thread.
I assume those are the frames where the footer would be sliding down - but I can't figure out where it is that I'm executing things on the main thread. Here's my code for LoginPage and LoginTask.
LoginPage.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_page);
login = (Button) findViewById(R.id.login);
username = (EditText) findViewById(R.id.username);
password = (EditText) findViewById(R.id.password);
footer = (LinearLayout) findViewById(R.id.footer);
// We must wait for the layout to be finalised before trying to find heights.
ViewTreeObserver vto = footer.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
initAnimations();
}
});
loading = (TextView) findViewById(R.id.loading);
login.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String mUsername = username.getText().toString();
String mPassword = password.getText().toString();
// Neither of these two things happen until after LoginTask is done.
footer.startAnimation(slideDown);
loading.setVisibility(TextView.VISIBLE);
tryLogin(mUsername, mPassword);
}
});
}
protected void tryLogin(String mUsername, String mPassword) {
Exception e;
String loginUrl = getString(R.string.login_url);
String clientId = getString(R.string.client_id);
String clientSecret = getString(R.string.client_secret);
LoginTask loginTask = (LoginTask) new LoginTask().execute(mUsername, mPassword, loginUrl, clientId, clientSecret);
if ((e = loginTask.getException()) != null) {
Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
} else {
JSONObject response;
try {
response = loginTask.get();
Log.d("login", response.toString());
if (!response.has("access_token")) {
loading.setVisibility(TextView.INVISIBLE);
footer.startAnimation(slideUp);
Toast.makeText(this, "Login error", Toast.LENGTH_LONG).show();
} else {
Intent i = new Intent(this, FullscreenWebView.class);
i.putExtra("accessToken", response.get("access_token").toString());
startActivity(i);
overridePendingTransition(0, 0);
}
} catch (InterruptedException e1) {
e1.printStackTrace();
Thread.currentThread().interrupt();
} catch (ExecutionException e1) {
e1.printStackTrace();
} catch (JSONException e1) {
e1.printStackTrace();
throw new RuntimeException(e);
}
}
}
LoginTask.java
class LoginTask extends AsyncTask<String, Void, JSONObject> {
private Exception exception;
#Override
protected JSONObject doInBackground(String... params) {
HttpURLConnection connection;
OutputStreamWriter request = null;
URL url = null;
JSONObject response = null;
String parameters = "grant_type=password&username="+params[0]+"&password="+params[1]+"&client_id="+params[3]+"&client_secret="+params[4];
try {
url = new URL(params[2]);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
request = new OutputStreamWriter(connection.getOutputStream());
request.write(parameters);
request.flush();
request.close();
// username or password is probably wrong
Log.d("login", ""+connection.getResponseCode());
if (connection.getResponseCode() != 200) {
return new JSONObject();
}
String line = "";
InputStreamReader isr = new InputStreamReader(connection.getInputStream());
BufferedReader reader = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
Log.d("login", sb.toString());
response = new JSONObject(sb.toString());
isr.close();
reader.close();
} catch (Exception e) {
this.exception = e;
}
return response;
}
}
I've also tried making LoginTask be a member class of LoginPage, and starting the animation in the onPreExecute() method, but that didn't change anything.
Any help is much appreciated!
When you use AsyncTask.get(), you are blocking the UI thread. As the animation runs on the UI thread, it appears as if it is not running (while in fact it is blocked by your long running tryLogin method).
Instead, you should move the code that relies on the result from the LoginTask to its onPostExecute method:
protected void tryLogin(String mUsername, String mPassword) {
String loginUrl = getString(R.string.login_url);
String clientId = getString(R.string.client_id);
String clientSecret = getString(R.string.client_secret);
new LoginTask().execute(mUsername, mPassword,
loginUrl, clientId, clientSecret);
}
LoginTask.java
class LoginTask extends AsyncTask<String, Void, JSONObject> {
private Exception exception;
#Override
protected JSONObject doInBackground(String... params) {
// Unchanged
}
public void onPostExecute(JSONObject response) {
if (exception != null) {
Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
} else {
Log.d("login", response.toString());
if (!response.has("access_token")) {
loading.setVisibility(TextView.INVISIBLE);
footer.startAnimation(slideUp);
Toast.makeText(this, "Login error", Toast.LENGTH_LONG).show();
} else {
Intent i = new Intent(this, FullscreenWebView.class);
i.putExtra("accessToken", response.get("access_token").toString());
startActivity(i);
overridePendingTransition(0, 0);
}
}
}
}
This is my Activity class where i use AsyncTask to get data from a server:
public class UserProfileActivity extends Activity {
private ImageView userImage;
private TextView userName;
private TextView userLocation;
private TextView editInfo;
private TextView chnageImage;
private TextView userScore;
private ListView friendsList;
public ArrayAdapter<String> adapter;
public int score;
public int level;
public String image;
public String fname;
public String lname;
public String city;
public int id;
public String email;
protected Activity activity = this;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.user_profile);
userImage = (ImageView) findViewById(R.id.profileImage);
userName = (TextView) findViewById(R.id.userName_profile);
userLocation = (TextView) findViewById(R.id.userLocation_profile);
editInfo = (TextView) findViewById(R.id.edit_profile);
chnageImage = (TextView) findViewById(R.id.changeImage_profile);
userScore = (TextView) findViewById(R.id.userScore_profile);
friendsList = (ListView) findViewById(R.id.friendsList);
new LongOperation().execute("");
}
private class LongOperation extends AsyncTask<String, Void, String> {
private InputStream is;
private StringBuilder sb;
private String result;
#Override
protected String doInBackground(String... params) {
try {
HttpPost httppost = new HttpPost(
"http://www.xxxxxxxxx.com/mobile/getProfileInfo");
HttpResponse response = SignUpActivity.httpclient
.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
}
try {
JSONObject jObj = new JSONObject(result);
String status = jObj.getString("status");
score = jObj.getInt("credits");
level = jObj.getInt("level");
image = jObj.getString("image");
fname = jObj.getString("fname");
lname = jObj.getString("lname");
city = jObj.getString("city");
id = jObj.getInt("user_id");
email = jObj.getString("email");
JSONArray friendsJsonArray = jObj.getJSONArray("friends");
int size = friendsJsonArray.length();
ArrayList<String> friendsNames = new ArrayList<String>();
String[] friendsIds = new String[size];
for (int i = 0; i < size; i++) {
friendsNames.add(friendsJsonArray.getJSONObject(i)
.getString("name"));
}
adapter = new ArrayAdapter<String>(getApplicationContext(),
R.layout.simple_listview_item, friendsNames);
} catch (Exception e) {
}
} catch (Exception e) {
}
return "Executed";
}
#Override
protected void onPostExecute(String result) {
friendsList.setAdapter(adapter);
userScore.setText(score + " points" + " level " + level);
userName.setText(fname + " " + lname);
userLocation.setText(city);
Bitmap bitmap = null;
try {
bitmap = BitmapFactory
.decodeStream((InputStream) new URL(image).getContent());
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e2) {
e2.printStackTrace();
}
userImage.setImageBitmap(bitmap);
}
#Override
protected void onPreExecute() {
}
#Override
protected void onProgressUpdate(Void... values) {
}
}
}
when this activity is loaded it shows all the default values and images and then changes when background code execution is competed(as excepted), but this takes 2-3 secs for which user will be seeing default values, which i dont want to. So how can i keep a spinner like this:
for 2-3 secs and then when the spinner disappears the activity must show the actual values.
Thank you
Refer the below code
private class FetchRSSFeeds extends AsyncTask<String, Void, Boolean> {
private ProgressDialog dialog = new ProgressDialog(HomeActivity.this);
/** progress dialog to show user that the backup is processing. */
/** application context. */
#Override
protected void onPreExecute() {
this.dialog.setMessage("Please wait");
this.dialog.show();
}
#Override
protected Boolean doInBackground(final String... args) {
try {
Utilities.arrayRSS = objRSSFeed
.FetchRSSFeeds(Constants.Feed_URL);
return true;
} catch (Exception e) {
Log.e("tag", "error", e);
return false;
}
}
#Override
protected void onPostExecute(final Boolean success) {
if (dialog.isShowing()) {
dialog.dismiss();
}
// Setting data to list adapter
setListData();
}
Do This:-
Declare the ProgressDialog at the Top.
ProgressDialog pd;
Start it in onPreExecute Method of Async Task.
pd=ProgressDialog.show(ActivityName.this,"","Please Wait",false);
Stop it in the onPostExecute Method.
pd.dismiss();
In onCreate method call some like below
mdialog=new Dialog(this);
new LongOperation().execute("");
Then override onPostExecute of AyncTask
#Override
protected void onPostExecute() {
runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
mdialog.dismiss();
}
});
}
I'm trying to show a loading icon to the user when the application makes a query to online Database. I've tried using a AnimationDrawable (I gave up because there was no need of a custom icon), ProgressDialog and ProgressBar.
The ProgressBar seems most appropriate, since I don't want a message, just a spinning icon. But I can not even make a ProgressBar appear on the screen, doesn't matter where I call it.
I've got the ProgressDialog appearing in screen, but it only appears after the server's response, and if I use dismiss() or cancel() it doesn't even appear at all.
I've had any success using AsyncTasks or Threads.
In the app, there is a class JogarActivity.java that attemps to show a list of options. It receives some parameters like the user id, and calls UserFunctions:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.jogar_layout);
Intent in = getIntent();
String url = this.getString(R.string.urlSite);
ArrayList<HashMap<String, String>> respostaList = new ArrayList<HashMap<String, String>>();
String idt = in.getStringExtra(TAG_ID);
primeiraPergunta = in.getBooleanExtra(TAG_PRIMEIRAPERGUNTA, true);
TextView insertPergunta = (TextView) findViewById(R.id.insertPergunta);
ListView insertRespostas = (ListView) findViewById(R.id.listResposta);
SharedPreferences settings = getSharedPreferences("PREFS_LOGIN", MODE_PRIVATE);
Integer idUsuario = settings.getInt("idUsuario", 0);
String idUser = idUsuario.toString();
if (primeiraPergunta){
UserFunctions userFunction = new UserFunctions();
json = userFunction.getJogar(idt, idUser);
}else{
try {
json = new JSONArray(in.getStringExtra(TAG_JSON));
json = json.getJSONArray(2);
} catch (JSONException e) {
e.printStackTrace();
}
}
Below is the getJogar function in userFunctions:
public JSONArray getJogar(String categoria, String usuarioId){
List params = new ArrayList();
params.add(new BasicNameValuePair("categoria", categoria));
params.add(new BasicNameValuePair("idUsuario", usuarioId));
JSONArray json = jsonParser.getJSONFromUrl(perguntaURL, params);
return json;
}
JSONParser.java is the class that makes the httpRequest:
public JSONArray getJSONFromUrl(String url, List params) {
// Making HTTP request
try {
// defaultHttpClient
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
// json = EntityUtils.toString(httpEntity);
// HttpEntity httpEntity2 = httpEntity;
json = EntityUtils.toString(httpEntity);
// is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
//then makes the JSON manipulation
As long as JSONParser and userFunctions aren't activities, I couldn't use ProgressDialogs inside them (Can't get the application context). All server requests are made in JSONParser.java, that's why i've first tried to put the ProgressDialog/ProgressBar there.
The closest that i've reached was using this code in JogarActivity (It shows the ProgressDialog, but after getting server's response. And if I use dismiss, it doesn't even appears)
final ProgressDialog loader = new ProgressDialog(JogarActivity.this);
loader.show();
//...the if-else code i've pasted above
loader.dismiss();
Even using runOnUiThread it doesn't works! I'm getting without options...
Thanks for all help.
this worked:
public class RegisterActivity extends Activity{
EditText reg_fullname;
EditText reg_email;
EditText reg_login;
EditText reg_password;
EditText reg_password2;
Spinner reg_country;
Spinner reg_genre;
EditText reg_birthday;
EditText reg_promocode;
Button btnRegister;
Context ctx = this;
ProgressDialog pDialog;
JSONArray json;
String status;
String msg;
String fullname;
String email;
String login;
String password;
String password2;
String country;
String genre;
String birthday;
String promocode;
boolean finishActivity = false;
/**
* #see android.app.Activity#onCreate(Bundle)
*/
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.register);
TextView loginScreen = (TextView) findViewById(R.id.link_to_login);
loginScreen.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
// Closing registration screen
// Switching to Login Screen/closing register screen
finish();
}
});
reg_fullname = (EditText) findViewById(R.id.reg_fullname);
reg_email = (EditText) findViewById(R.id.reg_email);
reg_login = (EditText) findViewById(R.id.reg_login);
reg_password = (EditText) findViewById(R.id.reg_password);
reg_password2 = (EditText) findViewById(R.id.reg_password2); //confirmação de senha
reg_country = (Spinner) findViewById(R.id.reg_country);
reg_genre = (Spinner) findViewById(R.id.reg_genre);
reg_birthday = (EditText) findViewById(R.id.reg_birthday);
reg_promocode = (EditText) findViewById(R.id.reg_promocode);
btnRegister = (Button) findViewById(R.id.btnRegister);
btnRegister.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
fullname = reg_fullname.getText().toString();
email = reg_email.getText().toString();
login = reg_login.getText().toString();
password = reg_password.getText().toString();
password2 = reg_password2.getText().toString();
country = reg_country.getSelectedItem().toString();
genre = reg_genre.getSelectedItem().toString();
birthday = reg_birthday.getText().toString();
promocode = reg_promocode.getText().toString();
boolean validation = true;
String message = "Campo de preencimento obrigatório";
if(fullname.equalsIgnoreCase("")){
reg_fullname.setError(message);
validation = false;
}
if(email.equalsIgnoreCase("")){
reg_email.setError(message);
validation = false;
}
if(!email.matches(".*#.*")){
reg_email.setError("O endereço de email não é válido");
validation = false;
}
if(login.equalsIgnoreCase("")){
reg_login.setError(message);
validation = false;
}
if(password.equalsIgnoreCase("")){
reg_password.setError(message);
validation = false;
}
if(password2.equalsIgnoreCase("")){
reg_password2.setError(message);
validation = false;
}
if(!password.equals(password2)){
reg_password2.setError("A confirmação de senha não confere");
validation = false;
}
if(birthday.equalsIgnoreCase("")){
reg_birthday.setError(message);
validation = false;
}
SimpleDateFormat bd = new SimpleDateFormat("dd/MM/yyyy");
if(bd.parse(birthday, new ParsePosition(0)) == null){
reg_birthday.setError("Esta data não é válida! Preencha novamente, usando o formato dd/mm/aaaa");
validation = false;
}
if(validation){
new Register().execute();
}
}
});
}
class Register extends AsyncTask<Void, Void, JSONArray>{
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ctx);
pDialog.setMessage("Aguarde...");
pDialog.setIndeterminate(true);
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected JSONArray doInBackground(Void... params) {
UserFunctions userFunction = new UserFunctions();
json = userFunction.newUser(fullname, email, login, password, country, genre, birthday, promocode);
return json;
}
protected void onPostExecute(JSONArray result) {
// dismiss the dialog once done
pDialog.dismiss();
final AlertDialog alertDialog = new AlertDialog.Builder(
RegisterActivity.this).create();
try {
status = json.getString(0);
msg = json.getString(1);
Log.d("Status", status);
} catch (JSONException e) {
Log.e("RegisterActiviry", "Error converting result " + e.toString());
e.printStackTrace();
status = null;
}
if (status.equalsIgnoreCase("erro")){
alertDialog.setTitle("Erro");
alertDialog.setMessage(msg);
}else if (status.equalsIgnoreCase("sucesso")){
alertDialog.setTitle("Sucesso!");
alertDialog.setMessage(msg);
finishActivity = true;
}else{
alertDialog.setTitle("Erro");
alertDialog.setMessage("Não foi possível realizar seu cadastro, tente novamente mais tarde.");
}
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
if(finishActivity){
finish();
}else{
alertDialog.dismiss();
}
}
});
alertDialog.show();
}
}
}
I'm new to Android development and I'm trying to code a little app which allows me to grab an external JSON file and parse it. I got this to work, however it wont work if I try to execute it in the background as an AsyncTask. Eclipse gives me the error
The method findViewById(int) is undefined for the type LongOperation
in this line:
TextView txtView1 = (TextView)findViewById(R.id.TextView01);
Here is my code:
public class Main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new LongOperation().execute();
}
}
class LongOperation extends AsyncTask<String, Void, String> {
private final Context LongOperation = null;
#Override
protected String doInBackground(String... params) {
try {
URL json = new URL("http://www.corps-marchia.de/jsontest.php");
URLConnection tc = json.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(tc.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
JSONArray ja = new JSONArray(line);
JSONObject jo = (JSONObject) ja.get(0);
TextView txtView1 = (TextView)findViewById(R.id.TextView01);
txtView1.setText(jo.getString("text") + " - " + jo.getString("secondtest"));
}
} catch (MalformedURLException e) {
Toast.makeText(this.LongOperation, "Malformed URL Exception: " + e, Toast.LENGTH_LONG).show();
} catch (IOException e) {
Toast.makeText(this.LongOperation, "IO Exception: " + e, Toast.LENGTH_LONG).show();
} catch (JSONException e) {
Toast.makeText(this.LongOperation, "JSON Exception: " + e, Toast.LENGTH_LONG).show();
}
return null;
}
#Override
protected void onPostExecute(String result) {
}
protected void onPreExecute() {
}
#Override
protected void onProgressUpdate(Void... values) {
ProgressDialog pd = new ProgressDialog(LongOperation);
pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pd.setMessage("Working...");
pd.setIndeterminate(true);
pd.setCancelable(false);
}
}
Any ideas on how to fix this?
Here is what you should do to make it work as you want. Use onPostExecude()
public class Main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new LongOperation(this).execute();
}
}
class LongOperation extends AsyncTask<String, Void, String> {
private Main longOperationContext = null;
public LongOperation(Main context) {
longOperationContext = context;
Log.v("LongOper", "Konstuktor");
}
#Override
protected String doInBackground(String... params) {
Log.v("doInBackground", "inside");
StringBuilder sb = new StringBuilder();
try {
URL json = new URL("http://www.corps-marchia.de/jsontest.php");
URLConnection tc = json.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(tc.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
JSONArray ja = new JSONArray(line);
JSONObject jo = (JSONObject) ja.get(0);
Log.v("line = ", "jo.getString() ="+jo.getString("text"));
sb.append(jo.getString("text") + " - " + jo.getString("secondtest")).append("\n");
}
} catch (MalformedURLException e) {
e.printStackTrace();
Log.v("Error", "URL exc");
} catch (IOException e) {
e.printStackTrace();
Log.v("ERROR", "IOEXECPTOIn");
} catch (JSONException e) {
e.printStackTrace();
Log.v("Error", "JsonException");
}
String result = sb.toString();
return result;
}
#Override
protected void onPostExecute(String result) {
Log.v("onPostExe", "result = "+result);
TextView txtView1 = (TextView)longOperationContext.findViewById(R.id.textView01);
txtView1.setText(result);
}
protected void onPreExecute() {
}
#Override
protected void onProgressUpdate(Void... values) {
ProgressDialog pd = new ProgressDialog(longOperationContext);
pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pd.setMessage("Working...");
pd.setIndeterminate(true);
pd.setCancelable(false);
}
}
The implementation of AsyncTask in one of the other answers is flawed. The progress dialog is being created every time within publishProgress, and the reference to the dialog is not visible outside the method. Here is my attempt:
public class Main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new LongOperation().execute();
}
class LongOperation extends AsyncTask<String, Void, String> {
ProgressDialog pd = null;
TextView tv = null;
#Override
protected void onPreExecute(){
tv = Main.this.findViewById(R.id.textvewid);
pd = new ProgressDialog(Main.this);
pd.setMessage("Working...");
// setup rest of progress dialog
}
#Override
protected String doInBackground(String... params) {
//perform existing background task
return result;
}
#Override
protected void onPostExecute(String result){
pd.dismiss();
tv.setText(result);
}
}
}
You are trying to do something which won't work. First of all you are inside of a class that extends AsyncTask so you won't have that method available as it is a method of the class Activity.
The second problem is that you are trying to do UI stuff in a method that is not synchronized with the UI thread. That is nothing you would want to do.
Process your JSON response in the doInBackground method and pass the result to the onPostExecute method where you will be able to handle UI stuff as it is synchronized with the UI thread.
The current setup you have will not make it easier for you to handle what you are trying to do anyway. You could make your LongOperation class a private class of your Activity class and define the TextView as a instance member. Grab it off the layout using findViewById inside of your OnCreate and modify (set text or whatever) inside the onPostExecute method of your AsyncTask.
I hope it is somewhat clear what I meant.
findViewById is method in Activity class. You should pass instance of your activity to your LongOperation when you create it. Then use that instance to call findViewById.