action_share_mainactivity

 public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.action_bar_share_menu, menu);
        MenuItem item = menu.findItem(R.id.menu_item_share);
        ShareActionProvider myShareActionProvider = (ShareActionProvider) item.getActionProvider();
        Intent myIntent = new Intent();
        myIntent.setAction(Intent.ACTION_SEND);
        myIntent.putExtra(Intent.EXTRA_TEXT, "TESTO EXTRA");
        myIntent.setType("text/plain");

        myShareActionProvider.setShareIntent(myIntent);

        return true;
 }