Set only single option in iOS - ios

Question

I have two custom round rect button and on this did tap event on image show.Like When we select gender there is only one option to select other automatically hide.but my gives when i touch first button than it select but when i touch second button no operation select.
My main moto is that i want to choose gender but in iOS no radio button use so i design custom and on click event set image.
calling api is a string type.
-(void)viewdidload
{
button = [UIButton buttonWithType:UIButtonTypeCustom];
callApi=#"MALE";//calling Api is a string type//
[button addTarget:self action:#selector(roundButtonDidTap:) forControlEvents:UIControlEventTouchUpInside];
}
-(void)roundButtonDidTap:(UIButton*)tappedButton
{
if([callApi isEqualToString:#"FEMALE"]) {
UIImage *btnImage = [UIImage imageNamed:#"bullet.png"];
[button setImage:btnImage forState:UIControlStateNormal];
}
if ([callApi isEqualToString:#"MALE"]) {
UIImage *btnImage = [UIImage imageNamed:#"bullet.png"];
[button2 setImage:btnImage forState:UIControlStateSelected];
button.imageView.hidden=YES;
}
}

Answer 1

try this code:
-(IBAction)selectMale:(id) sender{ // MALE BUTTON
UIButton *RadioButton1 = (UIButton*)sender;
[self radiobuttonAction:RadioButton1];
}
-(void)radiobuttonAction:(UIButton *)Button
{
if(![Button isSelected])
{
[Button setSelected:YES];
[Button setImage:[UIImage imageNamed:#"radio_active.png"] forState:UIControlStateSelected];
gender = #"Male";
[btnFemale setImage:[UIImage imageNamed:#"radio.png"] forState:UIControlStateSelected];
[btnFemale setSelected:NO];
}
else
{
[Button setSelected:NO];
[Button setImage:[UIImage imageNamed:#"radio.png"] forState:UIControlStateNormal];
}
}
-(IBAction)selectFemale:(id) sender{
UIButton *RadioButton1 = (UIButton*)sender;
[self radiobuttonActionFemale:RadioButton1];
}
-(void)radiobuttonActionFemale:(UIButton *)Button
{
if(![Button isSelected])
{
[Button setSelected:YES];
[Button setImage:[UIImage imageNamed:#"radio_active.png"] forState:UIControlStateSelected];
gender = #"Female";
[btnMale setImage:[UIImage imageNamed:#"radio.png"] forState:UIControlStateSelected];
[btnMale setSelected:NO];
}
else
{