我来晚了一点，但是我采用了PetahChristian的解决方案，并以扩展的形式创建了Swift版本。这对我有用。我发现，当您尝试使用常规名称来使用字体名称和大小来获取字体时，它总是在字体文件的主捆绑包中查找，并且没有将捆绑包标识符作为参数的方法。如果苹果能制造一款，那将是很好的。

迅速：

public extension UIFont {

    public static func jbs_registerFont(withFilenameString filenameString: String, bundle: Bundle) {

        guard let pathForResourceString = bundle.path(forResource: filenameString, ofType: nil) else {
            print("UIFont+:  Failed to register font - path for resource not found.")
            return
        }

        guard let fontData = NSData(contentsOfFile: pathForResourceString) else {
            print("UIFont+:  Failed to register font - font data could not be loaded.")
            return
        }

        guard let dataProvider = CGDataProvider(data: fontData) else {
            print("UIFont+:  Failed to register font - data provider could not be loaded.")
            return
        }

        guard let font = CGFont(dataProvider) else {
            print("UIFont+:  Failed to register font - font could not be loaded.")
            return
        }

        var errorRef: Unmanaged<CFError>? = nil
        if (CTFontManagerRegisterGraphicsFont(font, &errorRef) == false) {
            print("UIFont+:  Failed to register font - register graphics font failed - this font may have already been registered in the main bundle.")
        }
    }

}

用法示例：

UIFont.jbs_registerFont(
    withFilenameString: "Boogaloo-Regular.ttf",
    bundle: Bundle(identifier: "com.JBS.JBSFramework")!
)