Android - Enabling MenuItems by code

Question

Hi

I need to enable a MenuItem when a previous screen (Activity) returns.

I tried this code:

... ((MenuItem)findViewById(R.id.menu_how)).setEnabled(true); ...

but a null pointer exception is launched.

BTW, the menu_how is set to false in xml; and the code is part of onActivityResult(int requestCode, int resultCode, Intent data) call.

Answer 1

where are you calling this? (Sorry, didn't read carefully) I think you need to call it after the menu is inflated (usually in OnCreateOptionsMenu). To do this, you can set a variable to true when the other Activity returns, then do ((MenuItem)findViewById(R.id.menu_how)).setEnabled(mMyBooleanField) in OnCreateOptionsMenu after the call to inflater.inflate.

Edit: To accomplish this in code, it might look something like this:

At the top of the class (along with all the other class members):
Boolean mEnableMenuItem = false;

In OnCreateOptionsMenu:
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.options_main, menu); ((MenuItem)findViewById(R.id.menu_how)).setEnabled(mEnableMenuItem );

In OnActivityResult:
mEnableMenuItem = true;