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

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)
          }
        }
     }

要在UIButton内右对齐图像，请尝试下面的代码

btn.contentHorizontalAlignment = .right

子类化和覆盖layoutSubviews可能是你最好的方法。

引用自:iPhone UIButton -图像位置

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);
    }

在界面构建器中，您可以为UIButton配置选项边缘插入，分别为三个部分:内容，图像，标题

Xcode 8: