iphone - iOS how to make slider stop at discrete points

Question

I would like to make a slider stop at discrete points that represent integers on a timeline. What's the best way to do this? I don't want any values in between. It would be great if the slider could "snap" to position at each discrete point as well.

Answer 1

The steps that I took here were pretty much the same as stated in jrturton's answer but I found that the slider would sort of lag behind my movements quite noticeably. Here is how I did this:

Put the slider into the view in Interface Builder. Set the min/max values of the slider. (I used 0 and 5)

In the .h file:

@property (strong, nonatomic) IBOutlet UISlider *mySlider;
- (IBAction)sliderChanged:(id)sender;

In the .m file:

- (IBAction)sliderChanged:(id)sender 
{
    int sliderValue;
    sliderValue = lroundf(mySlider.value);
    [mySlider setValue:sliderValue animated:YES];
}

After this in Interface Builder I hooked up the 'Touch Up Inside' event for the slider to File's Owner, rather than 'Value Changed'. Now it allows me to smoothly move the slider and snaps to each whole number when my finger is lifted.

Thanks @jrturton!

UPDATE - Swift:

@IBOutlet var mySlider: UISlider!

@IBAction func sliderMoved(sender: UISlider) {
    sender.setValue(Float(lroundf(mySlider.value)), animated: true)
}

Also if there is any confusion on hooking things up in the storyboard I have uploaded a quick example to github: https://github.com/nathandries/StickySlider