Swift使用CG和CI framework画棋盘

一方面我们可以直接用Core Image框架画棋盘,代码如下:

func drawCheckerboard(){
        UIGraphicsBeginImageContextWithOptions(CGSize(width:512,height:512), false, 0)
        let context = UIGraphicsGetCurrentContext()
        context?.setFillColor(UIColor.black.cgColor) for row in 0..<8{ for col in 0..<8{ if row%2 == 0{ if col%2 == 0{
                        context?.fill(CGR