Listener for BACK-button

Question

How I can get any action for back-button when the alert dialog is shown? I have to ask user "Do you really want discard changes?"

At this time there is alert dialog for input on the screen.

http://stackoverflow.com/a/7080331/1179430 – GAntoine May 02 '16 at 18:13 — GAntoine, May 02 '16 at 18:13

score 5 · Accepted Answer · edited Feb 15 '18 at 16:53

5

Your initial question was not very clear on what you wanted to do. So if you want to show a dialog when a user presses the back button after having types something in the EditText- then you need to @Override the onBackPressed method in your Activity class.

@Override
public void onBackPressed() {
    // Here you want to show the user a dialog box
    new AlertDialog.Builder(context)
        .setTitle("Exiting the App")
        .setMessage("Are you sure?")
        .setPositiveButton("YES", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                // The user wants to leave - so dismiss the dialog and exit
                 finish();
                 dialog.dismiss();
            }
        }).setNegativeButton("NO", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                // The user is not sure, so you can exit or just stay 
                dialog.dismiss();
            }
        }).show();

}

You can look at the accepted answer here.

But if you only wanted to handle the back-button press on the Dialog itself, then there's already an answer for this question - basically you set an OnKeyListener on the dialog like this:

dialog.setOnKeyListener(new Dialog.OnKeyListener() {

      @Override
      public boolean onKey(DialogInterface arg0, int keyCode,KeyEvent event)
      {
         if (keyCode == KeyEvent.KEYCODE_BACK) {
               /* The user pressed back button - do whatever here.
               Normally you dismiss the dialog like dialog.dismiss(); */

             }
            return true;
            }
        });

Look at the accepted answer here.

edited Feb 15 '18 at 16:53

Edric

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answered May 02 '16 at 16:54

ishmaelMakitla

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So I have to do somthing like this? if (keyCode == KeyEvent.KEYCODE_BACK) { AlertDialog.Builder di = new AlertDialog.Builder(); .... } – Evgeny GooDi May 02 '16 at 16:57
You must declare the `dialog` first and then add `OnKeyListener` to it. Do you know how to do this? – ishmaelMakitla May 02 '16 at 17:06
Well... I'm not shure... But now i have the dialog from that i have to listen back-button. Not shure where your code have to be to work correct. – Evgeny GooDi May 02 '16 at 17:13
Please add the code where you have your dialog and I can show you how to add my code. – ishmaelMakitla May 02 '16 at 17:14
Update your question to include the code - it is better that way. – ishmaelMakitla May 02 '16 at 17:17
I see the update (although you pasted it as an answer) - let me confirm something - do you want to handle back button press, or do you want to handle click events for the two buttons on your dialog (positive and negative) - please confirm so I can advise further. – ishmaelMakitla May 02 '16 at 17:28
I have dialog for edit name. If user write something in TextView and push back-button a have to show new dialog "Are you shure?" – Evgeny GooDi May 02 '16 at 17:32
OK, that makes perfect sense - let me offer a suggestion. – ishmaelMakitla May 02 '16 at 17:37
Thanks! Its easy! )))))))))))))))))) – Evgeny GooDi May 02 '16 at 17:55
I am glad it helps - you can vote the answer if you think it is useful. – ishmaelMakitla May 02 '16 at 17:58

score 0 · Answer 2 · answered May 02 '16 at 17:19

0

builder.setNegativeButton(R.string.btn_rev, new DialogInterface.OnClickListener(){
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    //если что-то ввели и нажали Назад
                    if (edText.getText() != null) {
                       // onBackPressed(); //here's code for back-button
                    }

                }
            });

answered May 02 '16 at 17:19

Evgeny GooDi

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it's not an answer. It is my code for paste new code into this. – Evgeny GooDi May 02 '16 at 17:35

Listener for BACK-button

2 Answers2