swift: UIImage+Extension

extension UIImage {
    /// 颜色转化为图片
    class func imageWithColor(_ color: UIColor) -> UIImage {
        
        let rect = CGRect(x: 0, y: 0, width: 1, height: 1)
        UIGraphicsBeginImageContext(rect.size)

        let context = UIGraphicsGetCurrentContext()

        context?.setFillColor(color.cgColor)
        context?.fill(rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image!
    }
    
    /// image 去锯齿
    func setAntialiasedImage(_ size: CGSize, _ scale: CGFloat) -> UIImage{
        UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
        self.draw(in: CGRect(x: 1, y: 1, width: size.width-2, height: size.height-2))
        let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return image
    }
    
    
    //    MARK:  截屏使用
    func screenShotWithoutMask(shotView: UIView) -> UIImage {
         UIGraphicsBeginImageContextWithOptions(shotView.krSize, true, 0.0)
        shotView.drawHierarchy(in: CGRect(origin: CGPoint(x: 0, y: 0), size: CGSize(width: screenWidth, height: screenHeight)), afterScreenUpdates: false)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image!
    }
    
    
    //MARK: -  返回不同颜色的新图片
    func changeColor(color: UIColor) -> UIImage? {
        
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale);
        
        let context = UIGraphicsGetCurrentContext();
        context?.translateBy(x: 0, y: self.size.height)
        context?.scaleBy(x: 1.0, y: -1.0)
        context?.setBlendMode(.normal)
        
        let rect = CGRect.init(x: 0, y: 0, width: self.size.width, height: self.size.height)
        context?.clip(to: rect, mask: self.cgImage!)
        context?.setFillColor(color.cgColor)
        context?.fill(rect)
        
        let newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return newImage

    }
}