Actions in onActivityResult and “Error Can not per

问题:

Implementing an app where the user can log in I have the following situation: If the user is logged in perform the action else start the login activity for result and if the result is Activity.RESULT_OK do the action.

My problem is that the action to perfom is to show a DialogFragment, but calling

DialogFragment newFragment = MyDialogFragment.newInstance(mStackLevel);
newFragment.show(ft, "dialog")

in the onActivityResult callback throws an exception:

Caused by: java.lang.IllegalStateException:  
Can not perform this action after onSaveInstanceState

So how can I solve this? I'm thinking in raising a flag there and show the dialog in the onResume but I see this solution a little dirty

Edit: Added more code (Im following this example for showing the DialogFragment

When the action is requested by the user:

... 
if (!user.isLogged()){
 startActivityForResult(new Intent(cnt, Login.class), REQUEST_LOGIN_FOR_COMMENT);
}

In the same fragment

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_LOGIN_FOR_COMMENT && resultCode == Activity.RESULT_OK) {
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        DialogFragment newFragment = MyDialogFragment.newInstance();
        newFragment.show(ft, "dialog")
    }
}

And if the user logs in the Login activity calls;

setResult(Activity.RESULT_OK);
finish();

回答1:

Best thing I've come up with is to not use .show() but rather do this.

CheckinSuccessDialog dialog = new CheckinSuccessDialog();
//dialog.show(getSupportFragmentManager(), null);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(dialog, null);
ft.commitAllowingStateLoss();

回答2:

Here is the workaround that works fine for me.

private void alert(final String message) {
    Handler handler = new Handler(Looper.getMainLooper());
    handler.post(new Runnable() {
        public void run() {
            AlertDialogFragment alertDialogFragment = AlertDialogFragment.newInstance(message);
            alertDialogFragment.show(getFragmentManager(), ALERT_DIALOG_FRAGMENT);
        }
    });        
}

回答3:

If using a DialogFragment, the only thing that worked for me was to dismiss the Fragment with dissmissAllowingStateLoss()

回答4:

I simply check whether an activity is being destroyed.

if (!getActivity().isFinishing()) {
    DialogFragment fragment = MyFragment.newInstance();
    fragment.show(getActivity().getSupportFragmentManager(), MyFragment.TAG);
}

回答5:

Override show(Fragment manager, String tag) function with allowing state lose and change mDismissed = false; mShownByMe = true; from origibal function by reflection:

public class DialogParent extends DialogFragment {

    @Override
    public void show(FragmentManager manager, String tag) {
        try {
            Field mDismissed = DialogFragment.class.getDeclaredField("mDismissed");
            Field mShownByMe = DialogFragment.class.getDeclaredField("mShownByMe");
            mDismissed.setAccessible(true);
            mShownByMe.setAccessible(true);
            mDismissed.setBoolean(this, false);
            mShownByMe.setBoolean(this, true);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        FragmentTransaction ft = manager.beginTransaction();
        ft.add(this, tag);
        ft.commitAllowingStateLoss();
    }
}

回答6:

This real works.

CheckinSuccessDialog dialog = new CheckinSuccessDialog();
//dialog.show(getSupportFragmentManager(), null);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(dialog, null);
ft.commitAllowingStateLoss();

But but still bad, because got error “Activity has been destroyed”

ava.lang.IllegalStateException: Activity has been destroyed fragmentTransaction.commitAllowingStateLoss();

So my solution is add check if (!isFinishing()&&!isDestroyed())

CheckinSuccessDialog fragment = CheckinSuccessDialog.newInstance();

     if (fragment instanceof DialogFragment) {
                DialogFragment dialog = (DialogFragment) fragment;
                if (!dialog.isAdded()) {
                    fragmentTransaction.add(dialog, 
                          CheckinSuccessDialog.class.getName());
                    if (!isFinishing()&&!isDestroyed()) {
                        fragmentTransaction.commitAllowingStateLoss();
                    }
                }

on dismiss:

FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
        Fragment fragment = getSupportFragmentManager().findFragmentByTag(CheckinSuccessDialog.class.getName());
        if (fragment != null && fragment instanceof DialogFragment) {
            DialogFragment dialog = (DialogFragment) fragment;
            dialog.dismiss();
            if (!isFinishing()&&!isDestroyed()) {
                fragmentTransaction.commitAllowingStateLoss();
            }
        }

回答7:

This exception is thrown whenever a FragmentTrasaction is commited after FragmentManager has saved its state. The easy and clean way is to check if FragmentManager has already saved state before showing a DialogFragment.

if(!getSupportFragmentManager.isStateSaved()) {
    MyDialogFragment dialogFragment = new MyDialogFragment()
    dialogFragment.show(getSupportFragmentManager, TAG);
}