not appearing view

[M0TRIX]

this is my code. and i only see gray line

` let sliderCover = UILabel() let sliderMainView = UIView() var slider = RangeSlider()

@objc func priceAction(){

    let priceLabelSTR = UILabel()
    let priceTo = UILabel()
    let priceFrom = UILabel()

    let priceToLabel = UILabel()
    let priceFromLabel = UILabel()

    let PriceSubmitButton = UIButton()
    let PriceCancleButton = UIButton()

    PriceLabel.backgroundColor = Colors.lowBlue
    PriceLabel.textColor = .white

    view.addSubview(sliderMainView)
    sliderMainView.addSubview(slider)
    sliderMainView.addSubview(priceLabelSTR)
    sliderMainView.addSubview(priceFrom)
    sliderMainView.addSubview(priceTo)
    sliderMainView.addSubview(priceToLabel)
    sliderMainView.addSubview(priceFromLabel)
    sliderMainView.addSubview(PriceSubmitButton)
    sliderMainView.addSubview(PriceCancleButton)

    view.addSubview(sliderCover)

    sliderCover.frame = view.frame
    sliderCover.alpha = 0.5
    sliderCover.backgroundColor = UIColor.black

    sliderMainView.translatesAutoresizingMaskIntoConstraints=false
    sliderMainView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 0).isActive=true
    sliderMainView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0).isActive=true
    sliderMainView.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.3).isActive=true
    sliderMainView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive=true
    sliderMainView.backgroundColor = .white
    view.bringSubviewToFront(sliderMainView)
    sliderCover.bringSubviewToFront(sliderMainView)

    priceLabelSTR.translatesAutoresizingMaskIntoConstraints=false
    priceLabelSTR.trailingAnchor.constraint(equalTo: sliderMainView.trailingAnchor, constant: -16).isActive=true
    priceLabelSTR.topAnchor.constraint(equalTo: sliderMainView.topAnchor, constant: 6).isActive=true
    priceLabelSTR.textColor = Colors.lowBlue

    slider.translatesAutoresizingMaskIntoConstraints=false
    slider.trailingAnchor.constraint(equalTo: priceLabelSTR.trailingAnchor, constant: 0).isActive=true
    slider.leadingAnchor.constraint(equalTo: sliderMainView.leadingAnchor, constant: 10).isActive=true
    slider.topAnchor.constraint(equalTo: priceLabelSTR.bottomAnchor, constant: -6).isActive=true
    slider.bottomAnchor.constraint(equalTo: sliderMainView.bottomAnchor, constant: 0).isActive=true

    //slider.backgroundColor = Colors.yellow
    slider.addTarget(self, action: #selector(sliderAction(_:)), for: .valueChanged)
    slider.upperValue = 1000
    slider.lowerValue = 1000
    slider.maximumValue = maxPrice
    slider.minimumValue = minPrice
    slider.curvaceousness = 0
    slider.frame = sliderMainView.frame`

}