CODEWITHSUNDEEP
androidandroid-activity
kumar piyush
kumar piyush

Reputation: 173

Exiting an Android Application On back button

I have an application in which I have different activities. In 1 activity, I want that when the user presses the back button, I want the application to be closed and home screen is displayed

Code

public boolean onKeyDown(int keyCode, KeyEvent event) 
        {
            //Handle the back button
            if(keyCode == KeyEvent.KEYCODE_BACK) 
                {
                    //Ask the user if they want to quit
                    new AlertDialog.Builder(this)
                    .setIcon(android.R.drawable.ic_dialog_alert)
                    .setTitle("Exit")
                    .setMessage("Really Exit ?")
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() 
                        {
                            public void onClick(DialogInterface dialog, int which) 
                                {
                                 Intent intent = new Intent(Intent.ACTION_MAIN);
                                intent.addCategory(Intent.CATEGORY_HOME);
                                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                                startActivity(intent);
                                }
                        })
                    .setNegativeButton("No", null)
                    .show();
                    return true;
                }
            else 
                {
                return super.onKeyDown(keyCode, event);
                }
        }

When I run this and press the back button, the home screen is displayed, but when I run it for the second time, I get a console output as

ActivityManager: Warning: Activity not started, its current task has been brought to the front.

And the activity in which the back button is pressed gets displayed. I think the application does not get killed and runs in background. Just to mention, this is not the starting activity of my application.

Can somebody help me, I am beginner.

Upvotes: 1

Views: 18261

Answers (7)

Khan
Khan

Reputation: 7605

For each and every Intent you have used for going into other activity u have to follow this way for passing intent just pass flag to each intent as given below and after starting Activity using startActivity() u have to add finish() after that demo code as given below 

Intent i=new Intent(firstActivity.this,secondActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
finish();

Upvotes: 3

Kazekage Gaara
Kazekage Gaara

Reputation: 15052

You cannot kill your application at your will. The android OS will do it when it wishes to free the resources allocated to it. You cannot actually implement the exit application concept in android. The user can simply navigate away from your Activity and return to it. If it has to be restarted from the first Activity or resumed where it left, is upto the android OS, not you.

Read this post to understand the philosophy of how android apps should be designed and why you wouldn't want to exit at your will: Is quitting an application frowned upon?

Upvotes: 2

Anu
Anu

Reputation: 562

you need to include this class as such in your code.........

  public abstract class AppBaseActivity extends Activity {
public static final String FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION =    "com.hrupin.FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION";
private BaseActivityReceiver baseActivityReceiver = new BaseActivityReceiver();
public static final IntentFilter INTENT_FILTER = createIntentFilter();

private static IntentFilter createIntentFilter(){
    IntentFilter filter = new IntentFilter();
    filter.addAction(FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION);
    return filter;
}

protected void registerBaseActivityReceiver() {
    registerReceiver(baseActivityReceiver, INTENT_FILTER);
}

protected void unRegisterBaseActivityReceiver() {
    unregisterReceiver(baseActivityReceiver);
}

public class BaseActivityReceiver extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        if(intent.getAction().equals(FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION)){
            finish();
        }
    }
} 

protected void closeAllActivities(){
    sendBroadcast(new Intent(FINISH_ALL_ACTIVITIES_ACTIVITY_ACTION));
}
  }

Then you need to extend all other classes from this class just as in an example below:

    public class FirstActivity extends AppBaseActivity implements OnClickListener {
/** Called when the activity is first created. */

private Button buttonOpenNextActivity;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.first);
    registerBaseActivityReceiver();
    buttonOpenNextActivity = (Button)findViewById(R.id.buttonOpenNextActivity);
    buttonOpenNextActivity.setOnClickListener(this);
}

@Override
protected void onDestroy() {
    super.onDestroy();
    unRegisterBaseActivityReceiver();
}

@Override
public void onClick(View v) {
    /* OPEN SECOND ACTIVITY.*/
    startActivity(new Intent(this, SecondActivity.class));
}
  }

Another class:

       public class SecondActivity extends AppBaseActivity implements OnClickListener {
private Button buttonOpenNextActivity;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);
    registerBaseActivityReceiver();
    buttonOpenNextActivity = (Button)findViewById(R.id.buttonOpenNextActivity);
    buttonOpenNextActivity.setOnClickListener(this);
}

@Override
protected void onDestroy() {
    super.onDestroy();
    unRegisterBaseActivityReceiver();
}

@Override
public void onClick(View v) {
    /* OPEN THIRD ACTIVITY.*/
    startActivity(new Intent(this, ThirdActivity.class));
}
            }

Last Class:

      public class ThirdActivity extends AppBaseActivity  implements OnClickListener  {
private Button buttonCloseAllActivities;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.third);
    registerBaseActivityReceiver();
    buttonCloseAllActivities = (Button)findViewById(R.id.buttonCloseAllActivities);
    buttonCloseAllActivities.setOnClickListener(this);
}

@Override
protected void onDestroy() {
    super.onDestroy();
    unRegisterBaseActivityReceiver();
}

 @Override
protected void onBackPressed() {
    closeAllActivities();
    super.onBackPressed();
}
}

Now when you press back button in third activity all other activities will also be finished altogether.

1/ dont forget to register the reciever in onCreate and unregister() it in ondestroy().

Upvotes: 1

Krishna Suthar
Krishna Suthar

Reputation: 3075

Try this code :

@Override
public void onBackPressed()
{
      moveTaskToBack(true);
}

Also check this Link

Upvotes: 4

Anu
Anu

Reputation: 562

if you want to exit your application on back press then you have to finish all the previous activities when you press the back button on that screen for this you should use the concept of BROADCAST RECIEVER ...... means you have broadcast an intent on that back press which will finish all the previous activities.

Upvotes: 0

Harneet Kaur
Harneet Kaur

Reputation: 4497

Your question is not clear dear.

As per my knowledge you should use broadCast Reciever for finishing the application and passing the intent to home Screen.

MoreOver Warning is nothing , before running your application just press Enter in your code or give sm space and den save it and re- run you appication.It will work fine....

Upvotes: 0

Md Abdul Gafur
Md Abdul Gafur

Reputation: 6201

Add finish(); after that line startActivity(intent) it finish your activity.

Thanks

Upvotes: 1

Related Questions