 
 
 
-
-

    
}





        // 滑条
        self.addSubview(greySlider)
        self.addSubview(alphaSlider)
        
        // 自定义滑条
        greySlider.setThumbImage(getThumbImage(radius: 10), for: .normal)
        
        alphaSlider.setMinimumTrackImage(getTrackImage(color: UIColor.white, height: 4), for: .normal)
        alphaSlider.setMaximumTrackImage(getTrackImage(color: UIColor.white, height: 4), for: .normal)
        alphaSlider.setThumbImage(getThumbImage(radius: 10), for: .normal)
        
        greySlider.translatesAutoresizingMaskIntoConstraints = false
        alphaSlider.translatesAutoresizingMaskIntoConstraints =  false
        self.addConstraint(NSLayoutConstraint.init(item: greySlider, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 1, constant: 0))
