線を描く
let image:UIImage = self.getUIImageOfVerticalGrid(self.view.frame.size, start: 0.0, lineInterval: 10.0, lineThickness: 1.0, lineColorHex: "ff0000")
let iv:UIImageView = UIImageView(image:image)
iv.contentMode = UIViewContentMode.ScaleAspectFit
iv.frame = CGRectMake(0,0,self.view.frame.size.width,self.view.frame.size.height)
self.view.addSubview(iv)

func getUIImageOfVerticalGrid(size:CGSize, start:CGFloat=0.0, lineInterval:CGFloat=44.0, lineThickness:CGFloat=1.0, lineColorHex:String="D6D6D6") -> UIImage {
    return self.getUIImageOfGrid(false, size: size, start: start, lineInterval: lineInterval, lineThickness: lineThickness, lineColorHex: lineColorHex)
}
func getUIImageOfGrid(horizontal:Bool, size:CGSize, start:CGFloat=0.0, lineInterval:CGFloat=44.0, lineThickness:CGFloat=1.0, lineColorHex:String="D6D6D6") -> UIImage {
    let scale:CGFloat = UIScreen.mainScreen().scale
    UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
    let context:CGContextRef = UIGraphicsGetCurrentContext()
    CGContextSetLineWidth(context, 0.0)
    let color:rgbTuple = self.getColorTupleByColorHex(lineColorHex)
    CGContextSetRGBStrokeColor(context, color.r,color.g,color.b, 1.0)
    CGContextSetRGBFillColor(context, color.r,color.g,color.b, 1.0)
    let w:CGFloat = (horizontal) ? size.width : lineThickness / scale
    let h:CGFloat = (horizontal) ? lineThickness / scale : size.height
    var currentPosition:CGFloat = start
    let maxPosition:CGFloat = (horizontal) ? size.height : size.width
    while currentPosition < maxPosition {
        let x:CGFloat = (horizontal) ? 0.0 : currentPosition
        let y:CGFloat = (horizontal) ? currentPosition : 0.0
        CGContextFillRect(context, CGRectMake( x, y, w, h))
        currentPosition += lineInterval
    }
    let image:UIImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
}
func getColorTupleByColorHex(colorHex:String, alpha:CGFloat=1.0) -> (r:CGFloat,g:CGFloat,b:CGFloat){
    let colorScanner:NSScanner = NSScanner(string: colorHex)
    var color:UInt32 = 0
    colorScanner.scanHexInt(&color)
    let r:CGFloat = CGFloat((color & 0xFF0000) >> 16) / CGFloat(255.0);
    let g:CGFloat = CGFloat((color & 0x00FF00) >> 8)  / CGFloat(255.0);
    let b:CGFloat = CGFloat(color & 0x0000FF) / CGFloat(255.0);
    return (r: r, g: g, b: b)
}


結果
iOS Simulator Screen Shot 2015.07.22 16.09.11