我详细阐述了你对其他人的回答，并在UIDevice上进行了快速扩展。我喜欢快速枚举和“一切有序”&原子化。我已经创建了解决方案，工作在设备和模拟器。

优点: -界面简单，使用方法如UIDevice.current.isIPhoneX - UIDeviceModelType enum让你能够轻松地扩展模型特定的特性和你想在你的应用中使用的常量，例如拐角半径

劣势: -这是特定于型号的解决方案，而不是特定于分辨率的解决方案-例如，如果苹果将生产另一种具有相同规格的型号，这将无法正常工作，你需要添加另一种型号才能使其工作=>你需要更新你的应用程序。

extension UIDevice {

    enum UIDeviceModelType : Equatable {

        ///iPhoneX
        case iPhoneX

        ///Other models
        case other(model: String)

        static func type(from model: String) -> UIDeviceModelType {
            switch model {
            case "iPhone10,3", "iPhone10,6":
                return .iPhoneX
            default:
                return .other(model: model)
            }
        }

        static func ==(lhs: UIDeviceModelType, rhs: UIDeviceModelType) -> Bool {
            switch (lhs, rhs) {
            case (.iPhoneX, .iPhoneX):
                return true
            case (.other(let modelOne), .other(let modelTwo)):
                return modelOne == modelTwo
            default:
                return false
            }
        }
    }

    var simulatorModel: String? {
        guard TARGET_OS_SIMULATOR != 0 else {
            return nil
        }

        return ProcessInfo.processInfo.environment["SIMULATOR_MODEL_IDENTIFIER"]
    }

    var hardwareModel: String {
        var systemInfo = utsname()
        uname(&systemInfo)
        let machineMirror = Mirror(reflecting: systemInfo.machine)
        let model = machineMirror.children.reduce("") { identifier, element in
            guard let value = element.value as? Int8, value != 0 else { return identifier }
            return identifier + String(UnicodeScalar(UInt8(value)))
        }

        return model
    }

    var modelType: UIDeviceModelType {
        let model = self.simulatorModel ?? self.hardwareModel
        return UIDeviceModelType.type(from: model)
    }

    var isIPhoneX: Bool {
        return modelType == .iPhoneX
    }
}

检查设备型号/机器名称，不要在你的代码中直接使用点/像素计数，这是硬代码，对设备硬件没有意义，设备型号是设备类型匹配的唯一标识符。

#import <sys/utsname.h>

NSString* deviceName()
{
    struct utsname systemInfo;
    uname(&systemInfo);

    return [NSString stringWithCString:systemInfo.machine
                          encoding:NSUTF8StringEncoding];
}

结果:

@"iPhone10,3" on iPhone X (CDMA)
@"iPhone10,6" on iPhone X (GSM)

参考这个答案。

完整的代码实现:

#import <sys/utsname.h>

NSString * GetDeviceModel(void)
{
    static dispatch_once_t onceToken;
    static NSString *strModelID = nil;

    dispatch_once(&onceToken, ^{
#if TARGET_IPHONE_SIMULATOR
        strModelID = NSProcessInfo.processInfo.environment[@"SIMULATOR_MODEL_IDENTIFIER"];
#else
        struct utsname systemInfo;

        uname(&systemInfo);
        strModelID = [NSString stringWithCString:systemInfo.machine encoding:NSUTF8StringEncoding];
#endif
    });

    return strModelID;
}

// See the `Hardware strings` in https://en.wikipedia.org/wiki/List_of_iOS_devices
BOOL IsiPhoneX(void)
{
    NSString *strModelID = GetDeviceModel();

    return [strModelID isEqualToString:@"iPhone10,3"] || [strModelID isEqualToString:@"iPhone10,6"];
}

BOOL IsNotchiPhone(void)
{
    NSArray<NSString *> *notchiModels = @[
        @"iPhone10,3", @"iPhone10,6", // iPhone X
        @"iPhone11,2", @"iPhone11,4", @"iPhone11,6", // iPhone XS (Max)
        @"iPhone11,8", // iPhone XR
        @"iPhone12,1", @"iPhone12,3", @"iPhone12,5", // iPhone 11 (Pro (Max))
        @"iPhone13,1", @"iPhone13,2", @"iPhone13,3", @"iPhone13,4", // iPhone 12 ([mini]|[Pro (Max)])
    ];

    return [notchiModels containsObject:GetDeviceModel()];
}

#define IS_IPHONE (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
#define IS_IPHONE_X (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 812.0f)

根据@saswanb的回复，这是Swift 4的版本:

var iphoneX = false
if #available(iOS 11.0, *) {
    if ((UIApplication.shared.keyWindow?.safeAreaInsets.top)! > CGFloat(0.0)) {
        iphoneX = true
    }
}

SWIFT 4/5可重用扩展，支持iPhone 12

    extension UIDevice {
    
    enum `Type` {
        case iPhone_5_5S_5C_SE1
        case iPhone_6_6S_7_8_SE2
        case iPhone_6_6S_7_8_PLUS
        case iPhone_X_XS_12mini
        case iPhone_XR_11
        case iPhone_XS_11Pro_Max
        case iPhone_12_Pro
        case iPhone_12_Pro_Max
    }
    
    var hasHomeButton: Bool {
        switch type {
        case . iPhone_X_XS_12mini, . iPhone_XR_11, .iPhone_XS_11Pro_Max, . iPhone_XS_11Pro_Max, .iPhone_12_Pro, .iPhone_12_Pro_Max:
            return false
        default:
            return true
        }
    }
    
    var type: Type {
        if UI_USER_INTERFACE_IDIOM() == .phone {
        switch UIScreen.main.nativeBounds.height {
        case 1136:
            return .iPhone_5_5S_5C_SE1
        case 1334:
            return .iPhone_6_6S_7_8_SE2
        case 1920, 2208:
            return .iPhone_6_6S_7_8_PLUS
        case 2436:
            return .iPhone_X_XS_12mini
        case 2532:
            return .iPhone_12_Pro
        case 2688:
            return .iPhone_XS_11Pro_Max
        case 2778:
            return .iPhone_12_Pro_Max
        case 1792:
            return .iPhone_XR_11
        default:
            assertionFailure("Unknown phone device detected!")
            return .iPhone_6_6S_7_8_SE2
        }
    } else {
        assertionFailure("Unknown idiom device detected!")
        return .iPhone_6_6S_7_8_SE2
    }
   }
}

struct ScreenSize {
    static let width = UIScreen.main.bounds.size.width
    static let height = UIScreen.main.bounds.size.height
    static let maxLength = max(ScreenSize.width, ScreenSize.height)
    static let minLength = min(ScreenSize.width, ScreenSize.height)
    static let frame = CGRect(x: 0, y: 0, width: ScreenSize.width, height: ScreenSize.height)
}

struct DeviceType {
    static let iPhone4orLess = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.maxLength < 568.0
    static let iPhone5orSE = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.maxLength == 568.0
    static let iPhone678 = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.maxLength == 667.0
    static let iPhone678p = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.maxLength == 736.0
    static let iPhoneX = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.maxLength == 812.0

    static let IS_IPAD              = UIDevice.current.userInterfaceIdiom == .pad && ScreenSize.maxLength == 1024.0
    static let IS_IPAD_PRO          = UIDevice.current.userInterfaceIdiom == .pad && ScreenSize.maxLength == 1366.0
}