notifications - iOS alert banner/label? -

i apologize if question basic. have been googling around can't seem find api/reference drop down alert banner/label (i not know proper term this), therefore posting here.

this: label/banner has "please enter valid email address" in it.

so here questions:

• what proper term (alert banner? notification? label?)
• i trying accomplish similar functionality shown in image, if field invalid, "label/banner" expands underneath navigation bar message in it: if uilabel, simplest way of adding expand animation? if built in, since have seen bunch of apps alerting, please let me know called.

have here, i'm sure able find suite needs.

the basic idea uiview animate down top of screen (at basic). can lot fancier adding gradients, touch recognizers dismiss it, etc. pretty base line functionality this:

//create view hold label , add images or whatever, place off screen @ -100 uiview *alertview = [[uiview alloc] initwithframe:cgrectmake(0, -100, cgrectgetwidth(self.view.bounds), 100)];  //create label display message , add alertview uilabel *themessage = [[uilabel alloc] initwithframe:cgrectmake(0, 0, cgrectgetwidth(alertview.bounds), cgrectgetheight(alertview.bounds))]; themessage.text = @"i'm alert"; [alertview addsubview:themessage];  //add alertview view [self.view addsubview:alertview];  //create ending frame or want end on screen, in case 0 y origin cgrect newfrm = alertview.frame; newfrm.origin.y = 0;  //animate in [uiview animatewithduration:2.0f animations:^{     alertview.frame = newfrm; }];