要识别iPhone 4S，只需检查以下内容:

var isIphone4S: Bool {

    let width = UIScreen.main.bounds.size.width
    let height = UIScreen.main.bounds.size.height
    let proportions = width > height ? width / height : height / width

    return proportions == 1.5 && UIDevice.current.model == "iPhone"
}

添加到Arash的代码，我不关心我的应用程序使用什么模型，我只想知道什么样的设备，所以，我可以测试如下:

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
        {
            NSLog(@"I'm definitely an iPad");
    } else {
    NSString *deviceType = [UIDevice currentDevice].model;
                if([deviceType rangeOfString:@"iPhone"].location!=NSNotFound)
                {
                    NSLog(@"I must be an iPhone");

                } else {
                    NSLog(@"I think I'm an iPod");

                }
}

我进一步将大的“isEqualToString”块转换为设备类型、生成和逗号后的其他限定符(我称之为子生成)的位掩码分类。它被包装在一个类中，带有一个单例调用SGPlatform，避免了大量重复的字符串操作。代码可用https://github.com/danloughney/spookyGroup

这个类允许你做这样的事情:

if ([SGPlatform iPad] && [SGPlatform generation] > 3) {
    // set for high performance
}

and

switch ([SGPlatform deviceMask]) {
case DEVICE_IPHONE:
    break;
case DEVICE_IPAD:
    break;
case DEVICE_IPAD_MINI:
    break;
}

设备的分类在platformBits方法中。这个方法对于本文的读者来说应该非常熟悉。我根据设备的类型和年代对其进行了分类，因为我最感兴趣的是整体性能，但源代码可以调整以提供您感兴趣的任何分类，如视网膜屏幕、网络功能等。

你可以像这样使用UIDevice类:

NSString *deviceType = [UIDevice currentDevice].model;

if([deviceType isEqualToString:@"iPhone"])
    // it's an iPhone

我想添加一个私有API来检索设备的正面和外壳颜色:

UIDevice *device = [UIDevice currentDevice];
SEL selector = NSSelectorFromString([device.systemVersion hasPrefix:@"7"] ? @"_deviceInfoForKey:" :  @"deviceInfoForKey:");
if ([device respondsToSelector:selector]) {
    NSLog(@"DeviceColor: %@ DeviceEnclosureColor: %@", [device performSelector:selector withObject:@"DeviceColor"], [device performSelector:selector withObject:@"DeviceEnclosureColor"]);
}

我在博客上写过这方面的文章，并提供了一个示例应用程序:

http://www.futuretap.com/blog/device-colors/

更新平台字符串。

// Created from this thread: https://gist.github.com/Jaybles/1323251

// Apple TV
if ([platform isEqualToString:@"AppleTV2,1"])   return @"Apple TV 2G";
if ([platform isEqualToString:@"AppleTV3,1"])   return @"Apple TV 3G";
if ([platform isEqualToString:@"AppleTV3,2"])   return @"Apple TV 3G";
if ([platform isEqualToString:@"AppleTV5,3"])   return @"Apple TV 4G";

// Apple Watch
if ([platform isEqualToString:@"Watch1,1"])     return @"Apple Watch";
if ([platform isEqualToString:@"Watch1,2"])     return @"Apple Watch";

// iPhone
if ([platform isEqualToString:@"iPhone1,1"])    return @"iPhone 2G";
if ([platform isEqualToString:@"iPhone1,2"])    return @"iPhone 3G";
if ([platform isEqualToString:@"iPhone2,1"])    return @"iPhone 3GS";
if ([platform isEqualToString:@"iPhone3,1"])    return @"iPhone 4 (GSM)";
if ([platform isEqualToString:@"iPhone3,2"])    return @"iPhone 4 (GSM/2012)";
if ([platform isEqualToString:@"iPhone3,3"])    return @"iPhone 4 (CDMA)";
if ([platform isEqualToString:@"iPhone4,1"])    return @"iPhone 4S";
if ([platform isEqualToString:@"iPhone5,1"])    return @"iPhone 5 (GSM)";
if ([platform isEqualToString:@"iPhone5,2"])    return @"iPhone 5 (Global)";
if ([platform isEqualToString:@"iPhone5,3"])    return @"iPhone 5c (GSM)";
if ([platform isEqualToString:@"iPhone5,4"])    return @"iPhone 5c (Global)";
if ([platform isEqualToString:@"iPhone6,1"])    return @"iPhone 5s (GSM)";
if ([platform isEqualToString:@"iPhone6,2"])    return @"iPhone 5s (Global)";
if ([platform isEqualToString:@"iPhone7,2"])    return @"iPhone 6";
if ([platform isEqualToString:@"iPhone7,1"])    return @"iPhone 6 Plus";
if ([platform isEqualToString:@"iPhone8,1"])    return @"iPhone 6s";
if ([platform isEqualToString:@"iPhone8,2"])    return @"iPhone 6s Plus";
if ([platform isEqualToString:@"iPhone8,4"])    return @"iPhone SE";
if ([platform isEqualToString:@"iPhone9,1"])    return @"iPhone 7 (Global)";
if ([platform isEqualToString:@"iPhone9,3"])    return @"iPhone 7 (GSM)";
if ([platform isEqualToString:@"iPhone9,2"])    return @"iPhone 7 Plus (Global)";
if ([platform isEqualToString:@"iPhone9,4"])    return @"iPhone 7 Plus (GSM)";

// iPad
if ([platform isEqualToString:@"iPad1,1"])      return @"iPad 1";
if ([platform isEqualToString:@"iPad2,1"])      return @"iPad 2 (WiFi)";
if ([platform isEqualToString:@"iPad2,2"])      return @"iPad 2 (GSM)";
if ([platform isEqualToString:@"iPad2,3"])      return @"iPad 2 (CDMA)";
if ([platform isEqualToString:@"iPad2,4"])      return @"iPad 2 (Mid 2012)";
if ([platform isEqualToString:@"iPad3,1"])      return @"iPad 3 (WiFi)";
if ([platform isEqualToString:@"iPad3,2"])      return @"iPad 3 (CDMA)";
if ([platform isEqualToString:@"iPad3,3"])      return @"iPad 3 (GSM)";
if ([platform isEqualToString:@"iPad3,4"])      return @"iPad 4 (WiFi)";
if ([platform isEqualToString:@"iPad3,5"])      return @"iPad 4 (GSM)";
if ([platform isEqualToString:@"iPad3,6"])      return @"iPad 4 (Global)";

// iPad Air
if ([platform isEqualToString:@"iPad4,1"])      return @"iPad Air (WiFi)";
if ([platform isEqualToString:@"iPad4,2"])      return @"iPad Air (Cellular)";
if ([platform isEqualToString:@"iPad4,3"])      return @"iPad Air (China)";
if ([platform isEqualToString:@"iPad5,3"])      return @"iPad Air 2 (WiFi)";
if ([platform isEqualToString:@"iPad5,4"])      return @"iPad Air 2 (Cellular)";

// iPad Mini
if ([platform isEqualToString:@"iPad2,5"])      return @"iPad Mini (WiFi)";
if ([platform isEqualToString:@"iPad2,6"])      return @"iPad Mini (GSM)";
if ([platform isEqualToString:@"iPad2,7"])      return @"iPad Mini (Global)";
if ([platform isEqualToString:@"iPad4,4"])      return @"iPad Mini 2 (WiFi)";
if ([platform isEqualToString:@"iPad4,5"])      return @"iPad Mini 2 (Cellular)";
if ([platform isEqualToString:@"iPad4,6"])      return @"iPad Mini 2 (China)";
if ([platform isEqualToString:@"iPad4,7"])      return @"iPad Mini 3 (WiFi)";
if ([platform isEqualToString:@"iPad4,8"])      return @"iPad Mini 3 (Cellular)";
if ([platform isEqualToString:@"iPad4,9"])      return @"iPad Mini 3 (China)";
if ([platform isEqualToString:@"iPad5,1"])      return @"iPad Mini 4 (WiFi)";
if ([platform isEqualToString:@"iPad5,2"])      return @"iPad Mini 4 (Cellular)";

// iPad Pro
if ([platform isEqualToString:@"iPad6,3"])      return @"iPad Pro (9.7 inch/WiFi)";
if ([platform isEqualToString:@"iPad6,4"])      return @"iPad Pro (9.7 inch/Cellular)";
if ([platform isEqualToString:@"iPad6,7"])      return @"iPad Pro (12.9 inch/WiFi)";
if ([platform isEqualToString:@"iPad6,8"])      return @"iPad Pro (12.9 inch/Cellular)";

// iPod
if ([platform isEqualToString:@"iPod1,1"])      return @"iPod Touch 1G";
if ([platform isEqualToString:@"iPod2,1"])      return @"iPod Touch 2G";
if ([platform isEqualToString:@"iPod3,1"])      return @"iPod Touch 3G";
if ([platform isEqualToString:@"iPod4,1"])      return @"iPod Touch 4G";
if ([platform isEqualToString:@"iPod5,1"])      return @"iPod Touch 5G";
if ([platform isEqualToString:@"iPod7,1"])      return @"iPod Touch 6G";

// Simulator
if ([platform isEqualToString:@"i386"])         return @"Simulator";
if ([platform isEqualToString:@"x86_64"])       return @"Simulator";