         static var pushToCurrentVCFinished: Bool = false
         static var pushToNextVCFinished:Bool = false
         
+        static var navBarBackgroundImage: UIImage = UIImage()
+        
         static var navBarBarTintColor: UIColor = UIColor.defaultNavBarBarTintColor
         static var navBarBackgroundAlpha:CGFloat = 1.0
         static var navBarTintColor: UIColor = UIColor.defaultNavBarTintColor

extension UINavigationBar
{
    fileprivate struct AssociatedKeys {
        static var backgroundView:UIView = UIView()
    }
    
    fileprivate var backgroundView:UIView? {

    
    func wr_viewDidAppear(_ animated: Bool)
    {
        if let navBarBgImage = navBarBackgroundImage {
            navigationController?.setNeedsNavigationBarUpdate(backgroundImage: navBarBgImage)
        } else {
            navigationController?.setNeedsNavigationBarUpdate(barTintColor: navBarBarTintColor)
        }
        navigationController?.setNeedsNavigationBarUpdate(barBackgroundAlpha: navBarBackgroundAlpha)
        navigationController?.setNeedsNavigationBarUpdate(tintColor: navBarTintColor)
        navigationController?.setNeedsNavigationBarUpdate(titleColor: navBarTitleColor)
