要在UIButton内右对齐图像，请尝试下面的代码

btn.contentHorizontalAlignment = .right

Swift 4 & 5

改变UIButton图像的方向(RTL和LTR)

extension UIButton {
    func changeDirection(){
       isArabic ? (self.contentHorizontalAlignment = .right) : (self.contentHorizontalAlignment = .left)
        // left-right margin 
        self.imageEdgeInsets = UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)
        self.titleEdgeInsets = UIEdgeInsets(top: 0, left: 5, bottom: 0, right: 5)
    }
}

把@Piotr的答案变成了一个Swift扩展。请确保在调用此函数之前设置好图像和标题，以便按钮大小适当。

 extension UIButton {
    
    /// Makes the ``imageView`` appear just to the right of the ``titleLabel``.
    func alignImageRight() {
        if let titleLabel = self.titleLabel, imageView = self.imageView {
            // Force the label and image to resize.
            titleLabel.sizeToFit()
            imageView.sizeToFit()
            imageView.contentMode = .ScaleAspectFit
            
            // Set the insets so that the title appears to the left and the image appears to the right. 
            // Make the image appear slightly off the top/bottom edges of the button.
            self.titleEdgeInsets = UIEdgeInsets(top: 0, left: -1 * imageView.frame.size.width,
                bottom: 0, right: imageView.frame.size.width)
            self.imageEdgeInsets = UIEdgeInsets(top: 4, left: titleLabel.frame.size.width,
                bottom: 4, right: -1 * titleLabel.frame.size.width)
          }
        }
     }

我决定不使用标准的按钮图像视图，因为所提出的移动它的解决方案感觉很俗气。这让我获得了想要的美感，并且通过改变约束来重新定位按钮是很直观的:

extension UIButton {
    func addRightIcon(image: UIImage) {
        let imageView = UIImageView(image: image)
        imageView.translatesAutoresizingMaskIntoConstraints = false

        addSubview(imageView)

        let length = CGFloat(15)
        titleEdgeInsets.right += length

        NSLayoutConstraint.activate([
            imageView.leadingAnchor.constraint(equalTo: self.titleLabel!.trailingAnchor, constant: 10),
            imageView.centerYAnchor.constraint(equalTo: self.titleLabel!.centerYAnchor, constant: 0),
            imageView.widthAnchor.constraint(equalToConstant: length),
            imageView.heightAnchor.constraint(equalToConstant: length)
        ])
    }
}

这是我在swift 5.2上的工作

let sizeOfTitle: CGFloat = 80
let sizeOfImage: CGFloat = 20
yourButton.titleEdgeInsets = UIEdgeInsets(top: 0.0, left: -sizeOfImage , bottom: 0.0, right: sizeOfImage)
yourButton.imageEdgeInsets = UIEdgeInsets(top: 0.0, left: sizeOfTitle, bottom: 0.0, right: -sizeOfTitle)

在尝试了互联网上的多种解决方案后，我没有达到确切的要求。所以我最终编写了自定义实用程序代码。在将来帮助别人。 在swift 4.2上测试

// This function should be called in/after viewDidAppear to let view render
    func addArrowImageToButton(button: UIButton, arrowImage:UIImage = #imageLiteral(resourceName: "my_image_name") ) {
        let btnSize:CGFloat = 32
        let imageView = UIImageView(image: arrowImage)
        let btnFrame = button.frame
        imageView.frame = CGRect(x: btnFrame.width-btnSize-8, y: btnFrame.height/2 - btnSize/2, width: btnSize, height: btnSize)
        button.addSubview(imageView)
        //Imageview on Top of View
        button.bringSubviewToFront(imageView)
    }