iOS development edit box is ejected by the system soft keyboard occlusion problem

When we develop the registration interface, the last few registration conditions are often easily obscured by the system pop-up keyboard, such as:

Can see, mailbox conditions are obscured, how to solve it? I calculated the offset by the agent of the Uitextfield:

-(void) viewdidload{[Super viewdidload];//do no additional setup after loading the view, typically from a nib. Self.emailTextField.delegate = self;} -(void) textfielddidbeginediting: (Uitextfield *) textfield{//1. Frame CGRect frame = Self.emailt to get the blocked mailbox TextField    Extfield.frame; 2. Calculate the height (y-coordinate) of the bottom represented by the occluded TextField and the maximum height (y-coordinate) that can not be obscured by the keyboard int offset = FRAME.ORIGIN.Y + +-(self.view.frame.size        . height-216);            [UIView animatewithduration:0.3 animations:^{if (Offset > 0) {//Let the entire view offset the gap upward        Self.view.frame = CGRectMake (0,-offset, Self.view.frame.size.width, self.view.frame.size.height);    }    }];            }-(void) textfielddidendediting: (Uitextfield *) textfield{[UIView animatewithduration:0.3 animations:^{    After editing is reset to the original Self.view.frame = CGRectMake (0, 0, self.view.frame.size.width, self.view.frame.size.height); }];}

Result diagram: