尽管一些建议的答案非常有创意和聪明，但最简单的解决方案如下:

button.semanticContentAttribute = UIApplication.shared
    .userInterfaceLayoutDirection == .rightToLeft ? .forceLeftToRight : .forceRightToLeft

就这么简单。作为奖励，在从右到左的区域中，图像将位于左侧。

编辑:这个问题已经被问过几次了，这是iOS 9 +。

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。

这里是解决方案的UIButton与中心对齐的内容。 这段代码使图像右对齐，并允许使用imageEdgeInsets和titleEdgeInsets进行宝贵的定位。

用你的自定义类子类化UIButton并添加:

- (CGRect)imageRectForContentRect:(CGRect)contentRect {
    CGRect frame = [super imageRectForContentRect:contentRect];
    CGFloat imageWidth = frame.size.width;
    CGRect titleRect = CGRectZero;
    titleRect.size = [[self titleForState:self.state] sizeWithAttributes:@{NSFontAttributeName: self.titleLabel.font}];
    titleRect.origin.x = (self.frame.size.width - (titleRect.size.width + imageWidth)) / 2.0 + self.titleEdgeInsets.left - self.titleEdgeInsets.right;
    frame.origin.x = titleRect.origin.x + titleRect.size.width - self.imageEdgeInsets.right + self.imageEdgeInsets.left;
    return frame;
}

- (CGRect)titleRectForContentRect:(CGRect)contentRect {
    CGFloat imageWidth = [self imageForState:self.state].size.width;
    CGRect frame = [super titleRectForContentRect:contentRect];
    frame.origin.x = (self.frame.size.width - (frame.size.width + imageWidth)) / 2.0 + self.titleEdgeInsets.left - self.titleEdgeInsets.right;
    return frame;
}

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)
        ])
    }
}

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+