UISlider with increments of 5

Add a target like this:

slider.continuous = YES;
[slider addTarget:self
      action:@selector(valueChanged:) 
      forControlEvents:UIControlEventValueChanged];

And in the valueChanged function set the value to the closest value that is divisible by 5.

[slider setValue:((int)((slider.value + 2.5) / 5) * 5) animated:NO];

So if you need any interval other than 5 simply set it like so:

float interval = 5.0f;//set this
[slider setValue:interval*floorf((slider.value/interval)+0.5f) animated:NO];

A slightly more elegant solution in Swift could be something like this

let step: Float = 5
@IBAction func sliderValueChanged(sender: UISlider) {
  let roundedValue = round(sender.value / step) * step
  sender.value = roundedValue
  // Do something else with the value

}

This way you get steps of 5. You can read more about the setup in my post.

There is another way to active the stepper functionality. works in a general case

Example:

range of data is 0 - 2800 and I want the increments to be in 25 unit values. I would do the following

1. set up the range of the slider to be 0 - (maxRange/unitsteps).
2. when the value changed method runs use (int)slider.value * unitsteps .

in the example above my slider would be set in IB to range 0 - 112. and my code would be (int)slider.value * 25.

if you then have a text field that can be modified for direct input you would just do the opposite set the slider value to the [textfield.text intValue]/ unitsteps.

For anyone looking for the Swift syntax...

override func viewDidLoad() {
    super.viewDidLoad()
    mySlider.addTarget(self, action: "sliderValueDidChange:", forControlEvents: .ValueChanged)
}

func sliderValueDidChange(sender:UISlider!)
{
    //Set value to the nearest 5...
    print((Float)((Int)((sender.value + 2.5) / 5) * 5))
    sender.setValue((Float)((Int)((sender.value + 2.5) / 5) * 5), animated: false)
}

Alternatively, just create an Action function with the Assistant Editor (what I did ultimately)...

@IBAction func mySliderValueChanged(sender: UISlider) {
    //Set value to the nearest int
    sender.setValue(Float(roundf(sender.value)), animated: false)

}