Cannot edit action bar title after orientation

Question

I need to develop an app where it is possible to change the action bar title style dynamically.

In tried to achieve this by accessing the action bar title in the following way:

(TextView) findViewById( 
            Resources.getSystem().getIdentifier(
                                                "action_bar_title", 
                                                "id", 
                                                "android" 
                                                ) 
                        );

I then edit the style just like normal TextView.

This seems to work fine before the mobile phone changes orientation.

After the orientation changed however, I can still get the TextView ( i.e. not return null ) by the above code but changes to the textview are no longer reflected.

Might anybody know why?

==============================================================

Thanks for your quick reply, the code i used to modify the TextView :

@Override
public void onConfigurationChanged( Configuration newConfig )
{
    super.onConfigurationChanged( newConfig );

    int titleId = Resources.getSystem().getIdentifier( "action_bar_title", "id", "android" );
    TextView title = (TextView) activity.findViewById( titleId );
    title.setTextColor( Color.parseColor("#ff0000") );
    title.setBackgroundColor( Color.parseColor("#00ff00") );
    title.setText( ""+ new Random().nextInt(9999) );
}

After the orientation changed, method onConfigurationChanged is being triggered. However, the action bar title TextView are no longer reflected.

I can also use titleView.getText().toString() to get the correct text i assigned earlier.

However, the action bar title has no any visible changes. What i feel is the TextView i extracted is not the Action Bar title.

Consider also adding the code used to modify the TextView... — Kris, Sep 03 '14 at 15:37

score 0 · Answer 1 · answered May 29 '17 at 03:10

After the orientation changed, the app resources refreshed, the pointer will lose its way to the new title TextView.

So hacking the textview to change its style and content is not a good way. Use android.text.SpannableString can do the same effect but keep style after orientation.

SpannableString titleSpan = new SpannableString(getString(R.string.app_name));
titleSpan.setSpan(new TypefaceSpan(this, titleTypeface), 0, titleSpan.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
getSupportActionBar().setTitle(titleSpan);

Reference: https://developer.android.com/reference/android/text/SpannableString.html

Cannot edit action bar title after orientation

1 Answers1