Application should give a prompt on pressing back button

Question

I am developing an android application. I wish that when I press back button in my application, it should give me a prompt(kind of alert dialog) if I really wish to exit. I dont know where to put this alert dialog and what to write in the Yes button, where user wants to quit the application. Please help me.

This question has been asked a lot [1](http://stackoverflow.com/questions/7550505/override-android-back-button) [2](http://stackoverflow.com/questions/4969541/override-the-back-button-in-android) [3](http://stackoverflow.com/questions/4779954/disable-back-button-in-android) — Andy McSherry, Dec 18 '12 at 09:00

score 8 · Accepted Answer · edited Dec 18 '12 at 08:52

8

You can override OnBackPressed() Function.

  @Override
public void onBackPressed()
{
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Exit");
    builder.setMessage("Are You Sure?");

    builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                    finish();
            }
        });

    builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }
    });
    AlertDialog alert = builder.create();
    alert.show();
}

edited Dec 18 '12 at 08:52

Renjith

5,783
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answered Dec 18 '12 at 08:38

Arash GM

10,316
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2

Although every thing seems fine with this answer, it is not advisable to use System.exit(0); in android. – Android Dec 18 '12 at 08:42
1

Cheers, did the job for me :-D – Usman Riaz Apr 14 '13 at 20:40

score 3 · Answer 2 · answered Dec 18 '12 at 08:39

@Override
public void onBackPressed() {

AlertDialog.Builder alertDialog = new AlertDialog.Builder(
        AppDemoActivity.this);

alertDialog.setPositiveButton("Yes", new OnClickListener() {

    @Override
    public void onClick(DialogInterface dialog, int which) {
        finish();
    }
});

alertDialog.setNegativeButton("No", null);

alertDialog.setMessage("Do you want to exit?");
alertDialog.setTitle("AppTitle");
alertDialog.show();
}

Use this to show an alert on Back Pressed

score 2 · Answer 3 · answered Dec 18 '12 at 08:43

This is another way to Override Back button :

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event)  {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            Toast.makeText(getApplicationContext(), "Back Pressed", Toast.LENGTH_LONG).show();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

Thanks.

score 1 · Answer 4 · answered Dec 18 '12 at 08:36

1

You can override the onBackPressed to show the alert, and in the yes button finish the activity..

public void onBackPressed() {
    //show alert here
}

answered Dec 18 '12 at 08:36

Nermeen

15,883
5
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Rahul · Answer 5 · 2012-12-18T08:57:01.680

@Override
    private void onBackPressed() {

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
alertDialogBuilder.setTitle("Do you really want to exit?");
alertDialogBuilder
        .setMessage("Click yes to exit!")
        .setCancelable(false)
        .setPositiveButton("Yes",new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                // if this button is clicked, close
                // current activity
                ThisActivity.this.finish();
            }
          })
        .setNegativeButton("No",new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                // if this button is clicked, just close
                // the dialog box and do nothing
                dialog.cancel();
            }
        });             
        AlertDialog alertDialog = alertDialogBuilder.create(); 
        alertDialog.show();
  }

Application should give a prompt on pressing back button

5 Answers5