我创建了一个自定义类CircularButton，我可以在其中为图像设置自定义图像，backgroundColor，tintColor，并插入按钮的边缘。
它的工作正常，除了tintColor。 我希望能够设置tintColor，但如果我不提供一个，它应该保留我的图像的原始tintColor（呈现为模板图像）。

open class CircularButton: UIButton {

    public init(width: CGFloat, backgroundColor: UIColor? = nil, tintColor: UIColor? = nil, image: UIImage? = nil, contentMode: ContentMode? = nil, insets: UIEdgeInsets? = nil) {
        super.init(frame: .zero)

        self.backgroundColor = backgroundColor ?? .clear
        self.tintColor = tintColor ?? // issue is here
        self.imageEdgeInsets = insets ?? .zero
        self.imageView?.contentMode = contentMode ?? .scaleAspectFit

        setImage(image?.withRenderingMode(.alwaysTemplate), for: .normal)

        if width != 0 {
            widthAnchor.constraint(equalToConstant: width).isActive = true
        }

        heightAnchor.constraint(equalTo: widthAnchor).isActive = true
        clipsToBounds = true
    }

    override open func layoutSubviews() {
        super.layoutSubviews()

        layer.cornerRadius = frame.width / 2
    }

    public required init?(coder aDecoder: NSCoder) {
        fatalError()
    }
}

let likeButton = CircularButton(width: 45, backgroundColor: #colorLiteral(red: 0, green: 0, blue: 0, alpha: 0.5), tintColor: .white, image: UIImage(named: "heart"), insets: .init(top: 5, left: 5, bottom: 5, right: 5))

self.tintColor = tintColor ?? imageView?.tintColor

修复方法：.alwaysOriginal而不是.alwaysTemplate在这一行

setImage(image?.withRenderingMode(.alwaysTemplate), for: .normal)