How to use progress dialog in AsyncTask in android
I am developing an application that requires the user to log in. Login works via a URL. However, when I add an AsyncTask to add a progress dialog, the application doesn't change intent. I have tried every possible method that I know in vain. below is the code:
package com.epolicing;
import java.util.ArrayList;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class LoginActivity extends Activity implements OnClickListener{
Button loginButton;
EditText usernme,passwrd;
TextView error;
String username,password;
static final int Dialog_logging_in=1;
boolean userverified=false;
// Session Manager Class
SessionManager session;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
session = new SessionManager(getApplicationContext());
loginButton = (Button) findViewById(R.id.loginButton);
usernme = (EditText) findViewById(R.id.UserName);
passwrd=(EditText) findViewById(R.id.password);
username=usernme.getText().toString().trim();
password=passwrd.getText().toString().trim();
error=(TextView)findViewById(R.id.errorTextView);
loginButton.setOnClickListener(this);
}
protected Dialog onCreateDialog(int id){
Dialog dialog = null;
switch(id){
case Dialog_logging_in:
ProgressDialog.show(LoginActivity.this,"","Authenticating user...");
break;
default:
dialog=null;
}
return dialog;
}
public void onClick(View v) {
switch(v.getId()){
case R.id.loginButton:
String user,pass;
user=usernme.getText().toString();
pass=passwrd.getText().toString();
if(user.equals("")||pass.equals("")){
message();
}
else {
new log_in().execute(this);
}
break;
}
}
//login method
public void login() {
ArrayList<NameValuePair>postParameters=new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("username",usernme.getText().toString()));
postParameters.add(new BasicNameValuePair("password",passwrd.getText().toString().trim()));
//String valid="1";
String response=null;
try{
response=CustomHttpClient.executeHttpPost("http://10.0.2.2/epolicing/tologin.php",postParameters);
String res=response.toString();
res=res.replaceAll("\\s+","");
if(res.equals("0")) {
error.setText("Wrong password or username combination");
}
else {
String usern=usernme.getText().toString().trim();
session.createLoginSession(usern,res);
userverified=true;
//Intent intent=new Intent(LoginActivity.this,menu.class);
//startActivity(intent);
}
}
catch(Exception e){
error.setText(e.toString());
}
}
public void message(){
Context context=getApplicationContext();
CharSequence text="username and/or password cannot be blank";
int duration=Toast.LENGTH_LONG;
Toast toast=Toast.makeText(context, text, duration);
toast.show();
}
private class log_in extends AsyncTask<LoginActivity,Void,LoginActivity>{
@Override
protected void onPreExecute(){
showDialog(Dialog_logging_in);
}
@Override
protected LoginActivity doInBackground(LoginActivity... Params) {
login();
return null;
}
protected void onPostExecute(LoginActivity params){
super.onPostExecute(params);
//dismissDialog(Dialog_logging_in);
if(userverified==true){
Intent intent=new Intent(LoginActivity.this,menu.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
LoginActivity.this.startActivity(intent);
}
}
}
}
Here is the log:
01-20 19:36:53.685: E/WindowManager(1191): Activity com.epolicing.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40555c68 that was originally added here
01-20 19:36:53.685: E/WindowManager(1191): android.view.WindowLeaked: Activity com.epolicing.LoginActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40555c68 that was originally added here
01-20 19:36:53.685: E/WindowManager(1191): at android.view.ViewRoot.<init>(ViewRoot.java:258)
01-20 19:36:53.685: E/WindowManager(1191): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
01-20 19:36:53.685: E/WindowManager(1191): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
01-20 19:36:53.685: E/WindowManager(1191): at android.view.Window$LocalWindowManager.addView(Window.java:424)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.Dialog.show(Dialog.java:241)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.ProgressDialog.show(ProgressDialog.java:107)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.ProgressDialog.show(ProgressDialog.java:90)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.ProgressDialog.show(ProgressDialog.java:85)
01-20 19:36:53.685: E/WindowManager(1191): at com.epolicing.LoginActivity.onCreateDialog(LoginActivity.java:50)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.Activity.onCreateDialog(Activity.java:2482)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.Activity.createDialog(Activity.java:882)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.Activity.showDialog(Activity.java:2557)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.Activity.showDialog(Activity.java:2524)
01-20 19:36:53.685: E/WindowManager(1191): at com.epolicing.LoginActivity$log_in.onPreExecute(LoginActivity.java:120)
01-20 19:36:53.685: E/WindowManager(1191): at android.os.AsyncTask.execute(AsyncTask.java:391)
01-20 19:36:53.685: E/WindowManager(1191): at com.epolicing.LoginActivity.onClick(LoginActivity.java:71)
01-20 19:36:53.685: E/WindowManager(1191): at android.view.View.performClick(View.java:2485)
01-20 19:36:53.685: E/WindowManager(1191): at android.view.View$PerformClick.run(View.java:9080)
01-20 19:36:53.685: E/WindowManager(1191): at android.os.Handler.handleCallback(Handler.java:587)
01-20 19:36:53.685: E/WindowManager(1191): at android.os.Handler.dispatchMessage(Handler.java:92)
01-20 19:36:53.685: E/WindowManager(1191): at android.os.Looper.loop(Looper.java:123)
01-20 19:36:53.685: E/WindowManager(1191): at android.app.ActivityThread.main(ActivityThread.java:3683)
01-20 19:36:53.685: E/WindowManager(1191): at java.lang.reflect.Method.invokeNative(Native Method)
01-20 19:36:53.685: E/WindowManager(1191): at java.lang.reflect.Method.invoke(Method.java:507)
01-20 19:36:53.685: E/WindowManager(1191): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-20 19:36:53.685: E/WindowManager(1191): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-20 19:36:53.685: E/WindowManager(1191): at dalvik.system.NativeStart.main(Native Method)
Help would be much appreciated. Thank.
+3
source to share
1 answer
there is no need to return the current Activity instance from doInBackground
because it AsyncTask
is an internal class of Activity, so you just use LoginActivity.this
to start the next activity. Modify your AsyncTask class like this:
private class log_in extends AsyncTask<String,Void,String>{
ProgressDialog pDialog;
@Override
protected void onPreExecute(){
pDialog = new ProgressDialog(LoginActivity.this);
pDialog.setMessage("Authenticating user...");
pDialog.show();
}
@Override
protected String doInBackground(String... params) {
login();
return null;
}
protected void onPostExecute(String params){
super.onPostExecute(params);
pDialog.dismiss();
if(userverified==true){
Intent intent=new Intent(LoginActivity.this,menu.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
LoginActivity.this.startActivity(intent);
}
else{
error.setText("Wrong password or username combination");
}
}
}
because it is not possible to update the UI elements from doInBackground
and you are trying to set the textview inside the method login()
instead of changing the text of the Textview, just douserverified==false
+14
source to share