let layer = CAGradientLayer()
layer.frame = view.bounds
///設定顔色
layer.colors = [color("61ccc8").cgColor,color("61ccc8").cgColor,kRGBColorAlpha(r: 97, g: 204, b: 200, alpha: 0.1).cgColor]
///設定顔色漸變的位置 (我這裡是橫向 中間點開始變化)
layer.locations = [0,0.5,1]
///開始的坐标點
layer.startPoint = CGPoint(x: 0, y: 0)
///結束的坐标點
layer.endPoint = CGPoint(x: 1, y: 0)
view.layer.addSublayer(layer)