这是一个UIImage集合类，可以很方便的对图片的染料（着色），增加亮度（闪电）和降低亮度（黑）和其他扩展的功能模块。

在swift下实现图片染色

import UIKit

extension UIImage {

///  Just change a colored color image, is to change the image TintColo
///
/// - Parameter tintColor: Need to change the color of the color
/// - Returns: Returns an image
func imageWithTintColor (tintColor: UIColor? = nil, alpha: CGFloat) -> UIImage?  {

let rect = CGRect(x: 0.0, y: 0.0, width: self.size.width, height: self.size.height)

UIGraphicsBeginImageContextWithOptions(rect.size,false,self.scale)

draw(in: rect)

let ctx = UIGraphicsGetCurrentContext()

ctx!.setFillColor((tintColor?.cgColor)!)

ctx!.setAlpha(alpha);

ctx?.setBlendMode(.sourceAtop)

ctx!.fill(rect);

let result = UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()

return result
}
}

Usage To swift

override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.

let gift01ImageView = UIImageView(image: UIImage(named: "ic-gift"))

gift01ImageView.frame =  CGRect(x: 50.0, y: 50.0, width: 48.0, height: 48.0)
self.view!.addSubview(gift01ImageView)

let gift02ImageView = UIImageView(image: UIImage(named: "ic-gift")?.imageWithTintColor(tintColor: UIColor.blue, alpha: 0.5))

gift02ImageView.frame =  CGRect(x: 125.0, y: 50.0, width: 48.0, height: 48.0)
self.view!.addSubview(gift02ImageView)

}