Prevent dialog dismissal on screen rotation in Android

问题

I am trying to prevent dialogs built with Alert builder from being dismissed when the Activity is restarted.

If I overload the onConfigurationChanged method I can successfully do this and reset the layout to correct orientation but I lose sticky text feature of edittext. So in solving the dialog problem I have created this edittext problem.

If I save the strings from the edittext and reassign them in the onCofiguration change they still seem to default to initial value not what was entered before rotation. Even if I force an invalidate does seem to update them.

I really need to solve either the dialog problem or the edittext problem.

Thanks for the help.

回答1:

The best way to avoid this problem nowadays is by using a DialogFragment.

Create a new class which extends DialogFragment. Override onCreateDialog and return your old Dialog or an AlertDialog.

Then you can show it with DialogFragment.show(fragmentManager, tag).

Here's an example with a Listener:

public class MyDialogFragment extends DialogFragment {

    public interface YesNoListener {
        void onYes();

        void onNo();
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        if (!(activity instanceof YesNoListener)) {
            throw new ClassCastException(activity.toString() + " must implement YesNoListener");
        }
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return new AlertDialog.Builder(getActivity())
                .setTitle(R.string.dialog_my_title)
                .setMessage(R.string.dialog_my_message)
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        ((YesNoListener) getActivity()).onYes();
                    }
                })
                .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        ((YesNoListener) getActivity()).onNo();
                    }
                })
                .create();
    }
}

And in the Activity you call:

new MyDialogFragment().show(getSupportFragmentManager(), "tag"); // or getFragmentManager() in API 11+

This answer helps explain these other three questions (and their answers):

Android Best way of avoid Dialogs to dismiss after a device rotation
Android DialogFragment vs Dialog
How can I show a DialogFragment using compatibility package?

回答2:

// Prevent dialog dismiss when orientation changes
private static void doKeepDialog(Dialog dialog){
    WindowManager.LayoutParams lp = new WindowManager.LayoutParams();
    lp.copyFrom(dialog.getWindow().getAttributes());
    lp.width = WindowManager.LayoutParams.WRAP_CONTENT;
    lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
    dialog.getWindow().setAttributes(lp);
}

public static void doLogout(final Context context){     
        final AlertDialog dialog = new AlertDialog.Builder(context)
        .setIcon(android.R.drawable.ic_dialog_alert)
        .setTitle(R.string.titlelogout)
        .setMessage(R.string.logoutconfirm)
        .setPositiveButton("Yes", new DialogInterface.OnClickListener()
        {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                ...   
            }

        })
        .setNegativeButton("No", null)      
        .show();    

        doKeepDialog(dialog);
    }

回答3:

If you're changing the layout on orientation change I wouldn't put android:configChanges="orientation" in your manifest because you're recreating the views anyway.

Save the current state of your activity (like text entered, shown dialog, data displayed etc.) using these methods:

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
}

That way the activity goes through onCreate again and afterwards calls the onRestoreInstanceState method where you can set your EditText value again.

If you want to store more complex Objects you can use

@Override
public Object onRetainNonConfigurationInstance() {
}

Here you can store any object and in onCreate you just have to call getLastNonConfigurationInstance(); to get the Object.

回答4:

Just add android:configChanges="orientation" with your activity element in AndroidManifest.xml

Example:

<activity
            android:name=".YourActivity"
            android:configChanges="orientation"
            android:label="@string/app_name"></activity>

回答5:

A very easy approach is to create the dialogs from the method onCreateDialog() (see note below). You show them through showDialog(). This way, Android handles the rotation for you and you do not have to call dismiss() in onPause() to avoid a WindowLeak and then you neither have to restore the dialog. From the docs:

Show a dialog managed by this activity. A call to onCreateDialog(int, Bundle) will be made with the same id the first time this is called for a given id. From thereafter, the dialog will be automatically saved and restored.

See Android docs showDialog() for more info. Hope it helps somebody!

Note: If using AlertDialog.Builder, do not call show() from onCreateDialog(), call create() instead. If using ProgressDialog, just create the object, set the parameters you need and return it. In conclusion, show() inside onCreateDialog() causes problems, just create de Dialog instance and return it. This should work! (I have experienced issues using showDialog() from onCreate() -actually not showing the dialog-, but if you use it in onResume() or in a listener callback it works well).

回答6:

This question was answered a long time ago.

Yet this is non-hacky and simple solution I use for myself.

I did this helper class for myself, so you can use it in your application too.

Usage is:

PersistentDialogFragment.newInstance(
        getBaseContext(),
        RC_REQUEST_CODE,
        R.string.message_text,
        R.string.positive_btn_text,
        R.string.negative_btn_text)
        .show(getSupportFragmentManager(), PersistentDialogFragment.TAG);

 PersistentDialogFragment.newInstance(
        getBaseContext(),
        RC_EXPLAIN_LOCATION,
        "Dialog title", 
        "Dialog Message", 
        "Positive Button", 
        "Negative Button", 
        false)
    .show(getSupportFragmentManager(), PersistentDialogFragment.TAG);





public class ExampleActivity extends Activity implements PersistentDialogListener{

        @Override
        void onDialogPositiveClicked(int requestCode) {
                switch(requestCode) {
                  case RC_REQUEST_CODE:
                  break;
                }
        }

        @Override
        void onDialogNegativeClicked(int requestCode) {
                switch(requestCode) {
                  case RC_REQUEST_CODE:
                  break;
                }          
        }
}

回答7:

You can combine the Dialog's onSave/onRestore methods with the Activity's onSave/onRestore methods to keep the state of the Dialog.

Note: This method works for those "simple" Dialogs, such as displaying an alert message. It won't reproduce the contents of a WebView embedded in a Dialog. If you really want to prevent a complex dialog from dismissal during rotation, try Chung IW's method.

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
     super.onRestoreInstanceState(savedInstanceState);
     myDialog.onRestoreInstanceState(savedInstanceState.getBundle("DIALOG"));
     // Put your codes to retrieve the EditText contents and 
     // assign them to the EditText here.
}

@Override
protected void onSaveInstanceState(Bundle outState) {
     super.onSaveInstanceState(outState);
     // Put your codes to save the EditText contents and put them 
     // to the outState Bundle here.
     outState.putBundle("DIALOG", myDialog.onSaveInstanceState());
}

回答8:

Definitely, the best approach is by using DialogFragment.

Here is mine solution of wrapper class that helps to prevent different dialogs from being dismissed within one Fragment (or Activity with small refactoring). Also, it helps to avoid massive code refactoring if for some reasons there are a lot of AlertDialogs scattered among the code with slight differences between them in terms of actions, appearance or something else.

public class DialogWrapper extends DialogFragment {
    private static final String ARG_DIALOG_ID = "ARG_DIALOG_ID";

    private int mDialogId;

    /**
     * Display dialog fragment.
     * @param invoker  The fragment which will serve as {@link AlertDialog} alert dialog provider
     * @param dialogId The ID of dialog that should be shown
     */
    public static <T extends Fragment & DialogProvider> void show(T invoker, int dialogId) {
        Bundle args = new Bundle();
        args.putInt(ARG_DIALOG_ID, dialogId);
        DialogWrapper dialogWrapper = new DialogWrapper();
        dialogWrapper.setArguments(args);
        dialogWrapper.setTargetFragment(invoker, 0);
        dialogWrapper.show(invoker.getActivity().getSupportFragmentManager(), null);
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mDialogId = getArguments().getInt(ARG_DIALOG_ID);
    }

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return getDialogProvider().getDialog(mDialogId);
    }

    private DialogProvider getDialogProvider() {
        return (DialogProvider) getTargetFragment();
    }

    public interface DialogProvider {
        Dialog getDialog(int dialogId);
    }
}

When it comes to Activity you can invoke getContext() inside onCreateDialog(), cast it to the DialogProvider interface and request a specific dialog by mDialogId. All logic to dealing with a target fragment should be deleted.

Usage from fragment:

public class MainFragment extends Fragment implements DialogWrapper.DialogProvider {
    private static final int ID_CONFIRMATION_DIALOG = 0;

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        Button btnHello = (Button) view.findViewById(R.id.btnConfirm);
        btnHello.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DialogWrapper.show(MainFragment.this, ID_CONFIRMATION_DIALOG);
            }
        });
    }

    @Override
    public Dialog getDialog(int dialogId) {
        switch (dialogId) {
            case ID_CONFIRMATION_DIALOG:
                return createConfirmationDialog(); //Your AlertDialog
            default:
                throw new IllegalArgumentException("Unknown dialog id: " + dialogId);
        }
    }
}

You can read the complete article on my blog How to prevent Dialog being dismissed? and play with the source code.

回答9:

It seems that this is still an issue, even when "doing everything right" and using DialogFragment etc.

There is a thread on Google Issue Tracker which claims that it is due to an old dismiss message being left in the message queue. The provided workaround is quite simple:

    @Override
    public void onDestroyView() {
        /* Bugfix: https://issuetracker.google.com/issues/36929400 */
        if (getDialog() != null && getRetainInstance())
            getDialog().setDismissMessage(null);

        super.onDestroyView();
    }

Incredible that this is still needed 7 years after that issue was first reported.

回答10:

I had a similar problem: when the screen orientation changed, the dialog's onDismiss listener was called even though the user didn't dismiss the dialog. I was able to work around this by instead using the onCancel listener, which triggered both when the user pressed the back button and when the user touched outside of the dialog.

回答11:

Just use

ConfigurationChanges = Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize

and app will know how to handle rotation and screen size.

来源：https://stackoverflow.com/questions/7557265/prevent-dialog-dismissal-on-screen-rotation-in-android

标签

android

dialog

android-edittext

onconfigurationchanged