Swift添加字体到项目中

1. 下载字体，导入到项目文件夹。

2. 项目Info添加Fonts provided by application的item为字体文件名"xxx.ttf"。

3. 打印出所有字体名，找到导入的字体文件对应不同weight的字体。如果还是找不到，我也不知道怎么解决。

    for family in UIFont.familyNames.sorted() {
        for fontName in UIFont.fontNames(forFamilyName: family).sorted() {
            print(fontName)
        }
    }

4. 针对不同weight返回不同字体。

func getEnglishFont(ofSize size: CGFloat, weight: UIFont.Weight) -> UIFont {
        var font: UIFont? = nil
        
        switch weight {
        case .ultraLight:
            font = UIFont(name: "KumbhSans-Regular_ExtraLight", size: size)
        case .thin:
            font = UIFont(name: "KumbhSans-KumbhSans-Regular_Thin", size: size)
        case .light:
            font = UIFont(name: "KumbhSans-Regular_Light", size: size)
        case .regular:
            font = UIFont(name: "KumbhSans-Regular", size: size)
        case .medium:
            font = UIFont(name: "KumbhSans-Regular_Medium", size: size)
        case .semibold:
            font = UIFont(name: "KumbhSans-Regular_SemiBold", size: size)
        case .bold:
            font = UIFont(name: "KumbhSans-Regular_Bold", size: size)
        case .heavy:
            font = UIFont(name: "KumbhSans-Regular_ExtraBold", size: size)
        case .black:
            font = UIFont(name: "KumbhSans-Regular_Black", size: size)
        default:
            print("default font")
            font = UIFont(name: "KumbhSans-Regular", size: size)
        }

        var nonEmptyFont: UIFont = UIFont.systemFont(ofSize: size, weight: weight)
        if let tmpFont = font {
            nonEmptyFont = tmpFont
        } else {
            print("使用默认字体")
        }
        
        return nonEmptyFont
    }