Ios messagebar wrong position

i have a weird problem with the init size of the main view. the messagebar is half hidden until i open the keyboard and it resizes. after i leave the messagebar it is completely viewable for the rest of the session. it seams like view height 100% doesnt work on app init. this only happens on ios. so i thought Keyboard.show() & .hide() would the the trick if i call them onPageAfterIn but nothing happens. Again this command works only on android but not ios. it seams view-main has to recalculated which happen when i open & close the keyboard with a click.

so can anyone help me with the view-main height or the Keyboard.show() on ios?