编辑代码

var myString = "Hello world!     -  swift.jsrun.net"
print(myString)
func displayBackgroundView() {
        let h = backgroundView.frame.size.height
        let w = backgroundView.frame.size.width

        let padding : CGFloat = 15
        let margin : CGFloat = 30

        let grid_w=(w-margin*2-padding*CGFloat(cols-1))/CGFloat(cols)
        let grid_h=(h-margin*2-padding*CGFloat(rows-1))/CGFloat(rows)

        for i in 0..<rows {
            for j in 0..<cols {
        let x = margin + CGFloat(j) * (grid_w + padding) 
        let y = margin + CGFloat (i) * (grid_h + padding) 
        let fect = CGRect (x: X, y:y, width: grid_w, height: grid_h)

        let data = group [i*cols+j]
        var fileName = ""
        switch data {
        case "0":
            fileName ="GreenBlock”
        case "B"：
            fileName ="Banana"
        case "^":
            fileName ="Monkey_up"
        case "v":
            fileName ="Monkey_down"
        case "<":
            fileName ="Monkey_left"
        case ">":
            fileName ="Monkey_right"
        default:
            fileName = "GreenBlock"
        }

        let img = UIImage(named: fileName)
        let imgView = UIImageView(frame: rect)
        imgView.image = img
        self.backgroundView.addSubview(imgView)
      }
    }
}