如何在Swift中自定义UISlider值

Question

I create UISlider Programmatically. I try to customise UISlider value as 4.1, 4.2, 4.3, 4.4, 4.5, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 6.0, ... Anybody give me the solution

sliderDemo = UISlider(frame:CGRectMake(0, 0, 200,20))
    var numberOfSteps : NSInteger = numbers.count - 1
    sliderDemo.minimumValue = 6.5
    sliderDemo.maximumValue = 4.1
    sliderDemo.continuous = true
    sliderDemo.value = 4.0
    sliderDemo.addTarget(self, action: "sliderValueDidChange:", forControlEvents: .ValueChanged)
    self.view.addSubview(sliderDemo)

func sliderValueDidChange(sender:UISlider!)
{
    println("number:\(sender.value)")
}

Answer 1

I just create an example of a custom slider for you, in this case I am creating and adding it myself to the form but you can easily adapt to use the one from storyboard, all you need to do is to add your values to the numbers array, the result will be in the variable number in the valueChanged function, you can use observer, notifications or protocol to retrieve the value as it change, or simply call a function from there.

class ViewController: UIViewController {

    var slider:UISlider?
    // These number values represent each slider position
    var numbers = [1, 2, 3, 4, 5, 6, 7] //Add your values here
    var oldIndex = 0

    override func viewDidLoad() {
        super.viewDidLoad()
        slider = UISlider(frame: self.view.bounds)
        self.view.addSubview(slider!)

        // slider values go from 0 to the number of values in your numbers array
        var numberOfSteps = Float(numbers.count - 1)
        slider!.maximumValue = numberOfSteps;
        slider!.minimumValue = 0;

        // As the slider moves it will continously call the -valueChanged:
        slider!.continuous = true; // false makes it call only once you let go
        slider!.addTarget(self, action: "valueChanged:", forControlEvents: .ValueChanged)
    }
    func valueChanged(sender: UISlider) {
        // round the slider position to the nearest index of the numbers array
        var index = (Int)(slider!.value + 0.5);
        slider?.setValue(Float(index), animated: false)
        var number = numbers[index]; // <-- This numeric value you want
        if oldIndex != index{
            println("sliderIndex:\(index)")
            println("number: \(number)")
            oldIndex = index
        }
    }
}

I hope that helps you!