当标题发生变化时，只需更新插图即可。你需要在另一侧用等量的、相反的插页来补偿插页。

[thebutton setTitle:title forState:UIControlStateNormal];
thebutton.titleEdgeInsets = UIEdgeInsetsMake(0, -thebutton.imageView.frame.size.width, 0, thebutton.imageView.frame.size.width);
thebutton.imageEdgeInsets = UIEdgeInsetsMake(0, thebutton.titleLabel.frame.size.width, 0, -thebutton.titleLabel.frame.size.width);

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

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。

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:

在Piotr Tomasik的优雅解决方案的基础上:如果你想在按钮标签和图像之间有一点间距，那么包括在你的边缘嵌入如下(复制我的代码在这里完美地为我工作):

    CGFloat spacing          = 3;
    CGFloat insetAmount      = 0.5 * spacing;

    // First set overall size of the button:
    button.contentEdgeInsets = UIEdgeInsetsMake(0, insetAmount, 0, insetAmount);
    [button sizeToFit];

    // Then adjust title and image insets so image is flipped to the right and there is spacing between title and image:
    button.titleEdgeInsets   = UIEdgeInsetsMake(0, -button.imageView.frame.size.width - insetAmount, 0,  button.imageView.frame.size.width  + insetAmount);
    button.imageEdgeInsets   = UIEdgeInsetsMake(0, button.titleLabel.frame.size.width + insetAmount, 0, -button.titleLabel.frame.size.width - insetAmount);

感谢Piotr的解决方案!

Erik