约束条件呢?与semanticContentAttribute不同，它们不会改变语义。也许是这样的:

 button.rightAnchorconstraint(equalTo: button.rightAnchor).isActive = true

或者在Objective-C中:

[button.imageView.rightAnchor constraintEqualToAnchor:button.rightAnchor].isActive = YES;

警告:未经测试，iOS 9+

扩展UiButton并放入这些线条

    if let imageWidth = self.imageView?.frame.width {
        self.titleEdgeInsets = UIEdgeInsetsMake(0, -imageWidth, 0, imageWidth);
    }

    if let titleWidth = self.titleLabel?.frame.width {
        let spacing = titleWidth + 20
        self.imageEdgeInsets = UIEdgeInsetsMake(0, spacing, 0, -spacing);
    }

感谢Vitaliy Gozhenko

我只是想添加，你可以添加IB_DESIGNABLE之前，你的按钮@interface和设置你的按钮类在storyborad。然后你就可以在界面构建阶段实时观看它的布局，而无需启动应用程序

扩展的方法

使用扩展设置图像右侧自定义偏移

   extension UIButton {
    func addRightImage(image: UIImage, offset: CGFloat) {
        self.setImage(image, for: .normal)
        self.imageView?.translatesAutoresizingMaskIntoConstraints = false
        self.imageView?.centerYAnchor.constraint(equalTo: self.centerYAnchor, constant: 0.0).isActive = true
        self.imageView?.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -offset).isActive = true
    }
}

从2016年1月开始，所有这些答案都是不必要的。在接口构建器中，将视图语义设置为强制从右向左，或者如果你更喜欢编程的方式，semanticContentAttribute = . forcerighttolefleft这将导致图像出现在文本的右侧。

swift 3.0迁移 jasongregori给出的解

class ButtonIconRight: UIButton {
        override func imageRect(forContentRect contentRect: CGRect) -> CGRect {
            var imageFrame = super.imageRect(forContentRect: contentRect)
           imageFrame.origin.x = super.titleRect(forContentRect: contentRect).maxX - imageFrame.width
        return imageFrame
        }

        override func titleRect(forContentRect contentRect: CGRect) -> CGRect {
            var titleFrame = super.titleRect(forContentRect: contentRect)
            if (self.currentImage != nil) {
                titleFrame.origin.x = super.imageRect(forContentRect: contentRect).minX
            }
            return titleFrame
        }