Cài đặt Nativation Bar

func initBtnBar(){

        

        let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 30, height: 30))

        imageView.contentMode = .scaleAspectFit

        let image = UIImage(named: "logo-white.png")

        imageView.image = image

        navigationItem.titleView = imageView

        //navigationItem.titleView?.sizeToFit()

        

        

        let myBackButton = UIButton(type: UIButtonType.custom)

        myBackButton.frame = CGRect(x: 0, y: 0, width: 35.0, height: 35.0)

        //myBackButton.addTarget(self, action: #selector(self.btnMenuLeftClicked), for: .touchUpInside)

        myBackButton.setImage( UIImage(named: "icon-menu.png")?.resizedImageWithinRect( rectSize: CGSize(width: 35, height: 35)), for: .normal )

        

        let myBackButtonBtn = UIBarButtonItem(customView: myBackButton)

        

        let myBackButtonBtnMargin = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.fixedSpace, target: nil, action: nil)

        myBackButtonBtnMargin.width = -12

        self.navigationItem.leftBarButtonItems  = [myBackButtonBtnMargin,myBackButtonBtn]

        

        

        let myBackButtonRight = UIButton(type: UIButtonType.custom)

        myBackButtonRight.frame = CGRect(x: 0, y: 0, width: 35.0, height: 35.0)

        //myBackButtonRight.addTarget(self, action: #selector(self.btnMenuRightClicked), for: .touchUpInside)

        myBackButtonRight.setImage(UIImage(named: "icon_send_office.png")?.resizedImageWithinRect(rectSize: CGSize(width: 35, height: 35)), for: .normal)

        

        let myBackButtonRightBtn = UIBarButtonItem(customView: myBackButtonRight)

        

        let myBackButtonRightBtnMargin = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.fixedSpace, target: nil, action: nil)

        myBackButtonRightBtnMargin.width = -12

        self.navigationItem.rightBarButtonItems  = [myBackButtonRightBtnMargin,myBackButtonRightBtn]

        

        

 }

- Gắn thêm : 

extension UIImage {

    

    /// Returns a image that fills in newSize

    func resizedImage(newSize: CGSize) -> UIImage {

        // Guard newSize is different

        guard self.size != newSize else { return self }

        

        UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0);

        self.draw(in: CGRect(x:0, y:0, width:newSize.width,height: newSize.height))

        let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!

        UIGraphicsEndImageContext()

        return newImage

    }

    

    /// Returns a resized image that fits in rectSize, keeping it's aspect ratio

    /// Note that the new image size is not rectSize, but within it.

    func resizedImageWithinRect(rectSize: CGSize) -> UIImage {

        let widthFactor = size.width / rectSize.width

        let heightFactor = size.height / rectSize.height

        

        var resizeFactor = widthFactor

        if size.height > size.width {

            resizeFactor = heightFactor

        }

        

        let newSize = CGSize(width:size.width/resizeFactor,height: size.height/resizeFactor)

        let resized = resizedImage(newSize: newSize)

        return resized

    }

    

}