While passing Android DialogFragment arguments, onCreateDialog bundle agument is unexpectedly null

Question

I am trying to display a basic dialog in Android using a DialogFragment using an argument for the dialog message as described in StackOverflow thread and DialogFragment documentation . My problem is that the Bundle argument savedInstanceState in onCreateDialog always shows up as null, which means the activity displays an empty dialog box instead of one with a message. How can I get the non-null bundle contents from the newInstance factory method to show up in onCreateDialog? Or am I simply missing something else?

The only significant difference I see from the documentation is that I am using a non-static class. I want the positive dialog button to depend on the content of the message, so this is intentional.

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.DialogInterface;
import android.os.Bundle;

public class SampleDialog extends DialogFragment {
    public static final String DIALOG_MESSAGE = "dialogMessage";

    private String dialogMessage;

    // arguments are handled through factory method with bundles for lifecycle maintenance
    public SampleDialog(){
    }

    public static SampleDialog newInstance(String dialogMessage){
        SampleDialog fragment = new SampleDialog();
        Bundle args = new Bundle();
        args.putString(DIALOG_MESSAGE, dialogMessage);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        if(savedInstanceState != null) {
            dialogMessage = savedInstanceState.getString(DIALOG_MESSAGE);
        }

        // Use the Builder class for convenient dialog construction
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setMessage(dialogMessage)
                .setPositiveButton(R.string.dial, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        // will depend on content of dialogMessage
                    }
                })
                .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        // User cancelled the dialog
                    }
                });
        // Create the AlertDialog object and return it
        return builder.create();
    }
}

I am calling this from an activity this way:

SampleDialog myDialog = SampleDialog.newInstance("does not appear");
FragmentTransaction transaction = getFragmentManager().beginTransaction();
myDialog.show(transaction, TAG);

Answer 1

you have to use getArguments to retrieve the Bundle you set with setArguments

Instead of

if(savedInstanceState != null) {
     dialogMessage = savedInstanceState.getString(DIALOG_MESSAGE);
}

you should have something like:

Bundle bundle = getArguments();
if (bundle != null) {
    dialogMessage = bundle.getString(DIALOG_MESSAGE);
}

Answer 2

I had the same problem, you have to use getArguments , as Blackbelt said.

The savedInstanceState will be available when onSaveInstanceState ( documentation ) is called and some data is filled in outState , to be retrieved latter.