How to display AlertDialog in a Fragment?

Question

I want to display an alert dialog in my app. I am using fragments. I tried the below code to do this:

 AlertDialog ad = new AlertDialog.Builder(context)
            .create();
    ad.setCancelable(false);
    ad.setTitle(title);
    ad.setMessage(message);
    ad.setButton(context.getString(R.string.ok_text), new DialogInterface.OnClickListener() {

        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }
    });
ad.show();

but it was crashing and the error in logcat was:

04-18 15:23:01.770: E/AndroidRuntime(9424): android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application

From internet I came to know that the crash is due to context issue. I had given context as

context = this.getActivity().getApplicationContext();

I don't know what is the problem with this. Can anybody help me?

score 137 · Accepted Answer · answered Apr 18 '12 at 10:12

137

Replace context with getActivity().

The ApplicationContext should not be used for tasks such as creating Dialogs. As you are in a fragment you can instead get the Activity-Context simply by calling the Fragments getActivity() method.

answered Apr 18 '12 at 10:12

Jave

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4

What should do if getActivity() is null? – Sujith Thankachan Mar 17 '14 at 12:10
2

@SujithPt When `getActivity()` returns null, it means that the fragment is not attached to the activity and you should not show any dialogs. – Mousa Dec 08 '15 at 08:45
@SujithThankachan you can wait till the getActivity() is not null. I havenot tried it out though. – Sreekanth Karumanaghat May 03 '18 at 05:18
requireActivity() new method was added in [february 2018](https://developer.android.com/topic/libraries/support-library/revisions#27-1-0) which in case it return null it throws an exception. If you are sure this method will not return null because you are using between onAttach and onDetach you can use it to get ride ot the warning that getActivity() might return null. – Soon Santos Sep 02 '18 at 21:54

score 16 · Answer 2 · answered May 24 '14 at 12:34

More Information about this question (AlertDialog in a fragment, managed inside an event):

If you call AlertDialog within an event like onClick(View v) or onLongClick(View v) you can use

public boolean onClick(View v) {
    ...
    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(v.getContext());
    ...
}

score 10 · Answer 3 · answered Apr 18 '12 at 10:12

10

Try to use DialogFragment, DialogFragment is better when you use Fragments

answered Apr 18 '12 at 10:12

FUBUs

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can you please post a sample code for that?this is the first time i am hearing about DialogFragment – andro-girl Apr 18 '12 at 10:20
link is dead @FUBUs – Karan Harsh Wardhan Dec 14 '18 at 07:40
@andro-girl https://guides.codepath.com/android/using-dialogfragment – FindOutIslamNow Nov 06 '19 at 04:26

score 1 · Answer 4 · answered Feb 24 '18 at 12:50

I have had similar issues whereby I was trying to create an AlertDialog from a Fragment. A NullPointerException arose from it. Initially I did as follows:

AlertDialog alertDialog = new AlertDialog.Builder(getActivity()).create();

The NullPointerException occurred specifically when calling alertDialog.show() later on in the code. But after searching the documentation for AlertDialog.Builder(), there seemed to be another way to initialize it [AlertDialog.Builder Doc], which is to include a theme/resId as shown below:

AlertDialog alertDialog = new AlertDialog.Builder(getActivity(), R.style.Theme_AppCompat_Dialog_Alert).create();

This resolved the NullPointerException at hand. Hope this helps you as well!

score 0 · Answer 5 · answered Apr 19 '14 at 08:56

I used it in an adapter inside a listView, therefore I couldn't use getActivity(). In order to make it work I used getActivity() for the context in the instantiation of the adapter in the fragment:

this.adapter = new myAdapter(getActivity(), factory);

Later in the other class (the adapter's class) I was able to use getContext()and it worked.

score 0 · Answer 6 · answered Aug 03 '21 at 09:50

0

AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

answered Aug 03 '21 at 09:50

G.ONE

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duplicate answer to the accepted answer – BabyishTank Oct 27 '21 at 22:02

score -1 · Answer 7 · edited Apr 04 '17 at 05:42

-1

                       AlertDialog alert= null;
                        AlertDialog.Builder build= new AlertDialog.Builder(getActivity());
                        build.setTitle("title");
                        build.setItems(stringarrayname, new DialogInterface.OnClickListener() {

                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                // TODO Auto-generated method stub
                            //Toast.makeText(getActivity(), "hi", Toast.LENGTH_SHORT).show();   

                            }
                        });
                        build.create().show();

edited Apr 04 '17 at 05:42

Ashish Dwivedi

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answered Sep 23 '14 at 07:14

udaysagar

1

i got the alert dialog by using this code in fragments – udaysagar Sep 23 '14 at 07:15
this code is wrong, you should use alert= build.create(); alert.show(); – Rodolfo Abarca Feb 06 '16 at 23:02

score -1 · Answer 8 · answered May 18 '17 at 11:13

You can try this or use DialogFragment

private void showAlert(final int position) {
        new AlertDialog.Builder(getActivity().getApplicationContext())
                .setTitle("Delete entry")
                .setMessage("Are you sure you want to delete this entry?")
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                      //  deleteSuggestions(position);
                    }
                })
                .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // do nothing
                    }
                })
                .setIcon(android.R.drawable.ic_dialog_alert)
                .show();
    }

score -1 · Answer 9 · edited Apr 27 '20 at 06:01

-1

The solution is to replace by getActivity()

AlertDialog.Builder alert = new AlertDialog.Builder(getActivity(),R.style.MaDialog);

edited Apr 27 '20 at 06:01

David Buck

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answered Apr 27 '20 at 03:17

cimohamed

1

How to display AlertDialog in a Fragment?

9 Answers9