ios - How can I get the size of the keyboard on iPhone? -

i want keyboard size without using nsnotification. when press plus button, can replace keyboard custom uiview this:

then plus button pressed , view loaded:

how can achieve this?

i made same rookie mistake want here. problem write lot realize not want avoid standard flow provided ios team. example have bad time dealing issue 1 (there additional bar part of standard keyboard chinese locale):

i solved using other people's work dakeyboardcontrol project. not need attach observer (or if use dakeyboardcontrol - block) directly bar buttons, controller , check user trying , animate bar accordingly. in sources can see how keyboard's animation duration , timing function. may sound more complicated indeed is, give try.