Swift版本残家，復(fù)制可用袱衷，當(dāng)然也可以不擴(kuò)展UIDevice，在其他地方定義一個變量币他。目前更新到iPhone X尔当，后續(xù)更新可以參考這個資料庫莲祸。
OC版本，可以參考這篇文章椭迎。
注意：不要試圖在模擬器環(huán)境下試圖用這個方法獲取設(shè)備型號锐帜，因為返回的值都是simulator。還是老老實實根據(jù)屏幕尺寸做相應(yīng)的操作吧畜号。

public extension UIDevice {
    
    var modelName: String {
        var systemInfo = utsname()
        uname(&systemInfo)
        let machineMirror = Mirror(reflecting: systemInfo.machine)
        let identifier = machineMirror.children.reduce("") { identifier, element in
            guard let value = element.value as? Int8, value != 0 else { return identifier }
            return identifier + String(UnicodeScalar(UInt8(value)))
        }
        
        switch identifier {
        case "iPod5,1":                                 return "iPod Touch 5"
        case "iPod7,1":                                 return "iPod Touch 6"
        case "iPhone3,1", "iPhone3,2", "iPhone3,3":     return "iPhone 4"
        case "iPhone4,1":                               return "iPhone 4s"
        case "iPhone5,1", "iPhone5,2":                  return "iPhone 5"
        case "iPhone5,3", "iPhone5,4":                  return "iPhone 5c"
        case "iPhone6,1", "iPhone6,2":                  return "iPhone 5s"
        case "iPhone7,2":                               return "iPhone 6"
        case "iPhone7,1":                               return "iPhone 6 Plus"
        case "iPhone8,1":                               return "iPhone 6s"
        case "iPhone8,2":                               return "iPhone 6s Plus"
        case "iPhone8,4":                               return "iPhone SE"
        case "iPhone9,1", "iPhone9,3":                  return "iPhone 7"
        case "iPhone9,2", "iPhone9,4":                  return "iPhone 7 Plus"
        case "iPhone10,1", "iPhone10,4":                return "iPhone 8"
        case "iPhone10,2", "iPhone10,5":                return "iPhone 8 Plus"
        case "iPhone10,3", "iPhone10,6":                return "iPhone X"
            
        case "iPad2,1", "iPad2,2", "iPad2,3", "iPad2,4":return "iPad 2"
        case "iPad3,1", "iPad3,2", "iPad3,3":           return "iPad 3"
        case "iPad3,4", "iPad3,5", "iPad3,6":           return "iPad 4"
        case "iPad4,1", "iPad4,2", "iPad4,3":           return "iPad Air"
        case "iPad5,3", "iPad5,4":                      return "iPad Air 2"
        case "iPad2,5", "iPad2,6", "iPad2,7":           return "iPad Mini"
        case "iPad4,4", "iPad4,5", "iPad4,6":           return "iPad Mini 2"
        case "iPad4,7", "iPad4,8", "iPad4,9":           return "iPad Mini 3"
        case "iPad5,1", "iPad5,2":                      return "iPad Mini 4"
        case "iPad6,3", "iPad6,4":                      return "iPad Pro (9.7-inch)"
        case "iPad6,7", "iPad6,8":                      return "iPad Pro (12.9-inch)"
        case "iPad6,11", "iPad6,12":                    return "iPad (5th generation)"
        case "iPad7,1", "iPad7,2":                      return "iPad Pro (12.9-inch, 2nd generation)"
        case "iPad7,3", "iPad7,4":                      return "iPad Pro (10.5-inch)"
            
        case "AppleTV5,3":                              return "Apple TV"
        case "i386", "x86_64":                          return "Simulator"
        default:                                        return identifier
        }
    }   
}