使用多色更改 UIView 的背景颜色

Question

i want to make my UIView Background color like following image

when i press on button the view's background color will become like above. i was googling to much but not find a way.Can you please help me?

Answer 1

You can do this using CALayer.

1.Create a CAGradientLayer.

2.Set the layer's colours property to your rainbow colours.

3.set startPoint and the layer's endPoint as per your requirement.

4.Create a CAShapeLayer(for the shape) and set it as the gradient layer's mask.

Enjoy!!

Answer 2

To draw something like that you need to use core graphic. Core graphics provides gradient feature that can be use.

Links: http://www.raywenderlich.com/32925/core-graphics-tutorial-shadows-and-gloss

http://www.thinkandbuild.it/playing-around-with-core-graphics-core-animation-and-touch-events-part-1/

Answer 3

Step 1: Create an ENUM (for horizontal and vertical selection)

Step 2: Create an extension of UIView and apply it in any uiView.

Example:

enum GradientColorDirection
{
    case vertical
    case horizontal
}

extension UIView {

func createGradient(opacity: Float = 1, direction: GradientColorDirection = .vertical)
    {
        let colors: [UIColor] = [UIColor.red,
                                   UIColor.yellow,
                                   UIColor.green,
                                   UIColor.systemBlue,
                                   UIColor.blue,
                                   UIColor.systemPink,
                                   UIColor.red]
                  
          let gradientLayer = CAGradientLayer()
          gradientLayer.opacity = opacity
          gradientLayer.colors = colors.map { $0.cgColor }

          if case .horizontal = direction {
              gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
              gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.0)
          }

          gradientLayer.bounds = self.bounds
          gradientLayer.anchorPoint = CGPoint.zero
          self.layer.addSublayer(gradientLayer)
      }
}

Usage:

let gradientView: UIView
gradientView.createGradient()