问Swift中的自定义导航栏

EN

 var mainScreenSize : CGSize = UIScreen.mainScreen().bounds.size // Getting main screen size of iPhone

@IBOutlet weak var viewBG: UIView!
let imageObbj:UIImage! =   self.imageResize(UIImage(named: "YourImage")!, sizeChange: CGSizeMake(mainScreenSize.width, mainScreenSize.height))
self.viewBG.backgroundColor = UIColor(patternImage: image)

 func imageResize (imageObj:UIImage, sizeChange:CGSize)-> UIImage{

        let hasAlpha = false
        let scale: CGFloat = 0.0 // Automatically use scale factor of main screen

        UIGraphicsBeginImageContextWithOptions(sizeChange, !hasAlpha, scale)
        imageObj.drawInRect(CGRect(origin: CGPointZero, size: sizeChange))

        let scaledImage = UIGraphicsGetImageFromCurrentImageContext()
        return scaledImage
    }