iOS开发 编辑框被系统弹出的软键盘遮挡问题

我们在开发注冊界面的时候,最后几个注冊条件经常easy被系统弹出的键盘遮挡,例如以下图:

能够看见,邮箱条件被遮挡掉了,怎么解决呢?我是通过UITextField的代理加计算偏移量:

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.

    self.emailTextField.delegate = self;

}

- (void)textFieldDidBeginEditing:(UITextField *)textField{

    //  1.取得被遮挡的邮箱的textField的frame
    CGRect frame = self.emailTextField.frame;
    //  2.计算被遮挡的textField的bottom代表的高度(Y坐标) 与 能不被键盘遮挡的最大高度(Y坐标) 的距离
    int offset = frame.origin.y + 32 - (self.view.frame.size.height - 216);

    [UIView animateWithDuration:0.3 animations:^{

        if (offset > 0) {

            //  让整个view向上偏移差距
            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:^{

        //  编辑结束后重置为原来的
        self.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
    }];

}

结果图: