Question

My programe does get valuse from UISlider and send the value to its superclass through protocol.

child.h

-(void) valueA:(NSInteger *)vA valueB:(NSInteger *)vB;

and I call it in child.m

[self.delegate valueA:sliderA.value valueB:sliderB.value];

but it returns error says “incompatible type for argument 1 of valueA:vA:”
do I have to parse the value before I pass the value? or I just made wrong parameter?

Answer 1

-(void) valueA:(NSInteger *)vA valueB:(NSInteger *)vB;

That method should actually be

-(void) valueA:(CGFloat)vA valueB:(CGFloat)vB;

I changed NSInteger* to GCFloat for two reasons.

The value property of UISlider is a CGFloat, so converting to NSInteger would result in a lose of precision. If you don’t mind, you can change it back, but I’d explicitly cast it, so it’s more clear that’s what YOU want.

I removed the * because you are passing a value, not a reference.