iOS 15带来了一个更新，现在你可以用一种更简单而不混乱的方式来处理按钮中的图像放置。没有insets。

在XIB /故事板: 简单地设置按钮的“位置”属性为领先/训练/顶部/底部后，添加一个图像属性按钮。由于它是领导/培训，所以它支持RTL有一个额外的优势

**在代码中(编程方式):** 以编程方式使用“按钮配置”属性

这不是一个向后兼容的功能，只能在iOS15+中工作，正如WWDC '21 - https://developer.apple.com/videos/play/wwdc2021/10064/?time=236所演示的那样

开发人员文档:https://developer.apple.com/documentation/uikit/uibutton/configuration?changes=_4

子类化UIButton是完全没有必要的。相反，你可以简单地为图像设置一个高的左插入值，为标题设置一个小的右插入值。就像这样:

button.imageEdgeInsets = UIEdgeInsetsMake(0., button.frame.size.width - (image.size.width + 15.), 0., 0.);
button.titleEdgeInsets = UIEdgeInsetsMake(0., 0., 0., image.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)
        ])
    }
}

我最终创建了一个自定义按钮，允许从检查器设置图像。下面是我的代码:

import UIKit

@IBDesignable
class CustomButton: UIButton {

    @IBInspectable var leftImage: UIImage? = nil
    @IBInspectable var gapPadding: CGFloat = 0

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }
    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setup()
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        setup()
    }

    func setup() {

        if(leftImage != nil) {
            let imageView = UIImageView(image: leftImage)
            imageView.translatesAutoresizingMaskIntoConstraints = false

            addSubview(imageView)

            let length = CGFloat(16)
            titleEdgeInsets.left += length

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

你可以从检查器中调整空白填充的值来调整文本和图像之间的间距。

PS:使用了一些来自@Mark Hennings答案的代码部分

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)
          }
        }
     }

我把功劳都给了inspirre48。基于他的建议和其他问题，我想出了这个。子类UIButton并重写这些方法。

@implementation UIButtonSubclass

- (CGRect)imageRectForContentRect:(CGRect)contentRect
{
    CGRect frame = [super imageRectForContentRect:contentRect];
    frame.origin.x = CGRectGetMaxX(contentRect) - CGRectGetWidth(frame) -  self.imageEdgeInsets.right + self.imageEdgeInsets.left;
    return frame;
}

- (CGRect)titleRectForContentRect:(CGRect)contentRect
{
    CGRect frame = [super titleRectForContentRect:contentRect];
    frame.origin.x = CGRectGetMinX(frame) - CGRectGetWidth([self imageRectForContentRect:contentRect]);
    return frame;
}

@end