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
    }
   }
}

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()];
}

在看完所有的答案后，我最后是这么做的:

解决方案(兼容Swift 4.1)

extension UIDevice {
    static var isIphoneX: Bool {
        var modelIdentifier = ""
        if isSimulator {
            modelIdentifier = ProcessInfo.processInfo.environment["SIMULATOR_MODEL_IDENTIFIER"] ?? ""
        } else {
            var size = 0
            sysctlbyname("hw.machine", nil, &size, nil, 0)
            var machine = [CChar](repeating: 0, count: size)
            sysctlbyname("hw.machine", &machine, &size, nil, 0)
            modelIdentifier = String(cString: machine)
        }

        return modelIdentifier == "iPhone10,3" || modelIdentifier == "iPhone10,6"
    }

    static var isSimulator: Bool {
        return TARGET_OS_SIMULATOR != 0
    }
}

Use

if UIDevice.isIphoneX {
    // is iPhoneX
} else {
    // is not iPhoneX
}

Note

Pre Swift 4.1你可以检查应用程序是否在模拟器上运行，就像这样:

TARGET_OS_SIMULATOR != 0

从Swift 4.1开始，你可以使用目标环境平台条件检查应用程序是否在模拟器上运行:

#if targetEnvironment(simulator)
    return true
#else
    return false
#endif

(旧的方法仍然有效，但这个新方法更经得起未来的考验)

或者，你也可以查看“DeviceKit”pod。 安装完成后，检查设备所需要做的就是:

import DeviceKit
let device = Device()
if device == .iPhoneX {
  // place your code here
}

我认为苹果不希望我们手动检查设备是否有“notch”或“home indicator”，但有效的代码是:

-(BOOL)hasTopNotch{

    if (@available(iOS 11.0, *)) {

        float max_safe_area_inset = MAX(MAX([[[UIApplication sharedApplication] delegate] window].safeAreaInsets.top, [[[UIApplication sharedApplication] delegate] window].safeAreaInsets.right),MAX([[[UIApplication sharedApplication] delegate] window].safeAreaInsets.bottom, [[[UIApplication sharedApplication] delegate] window].safeAreaInsets.left));

        return max_safe_area_inset >= 44.0;

    }

    return  NO;

}

-(BOOL)hasHomeIndicator{

    if (@available(iOS 11.0, *)) {

        int iNumberSafeInsetsEqualZero = 0;

        if([[[UIApplication sharedApplication] delegate] window].safeAreaInsets.top == 0.0)iNumberSafeInsetsEqualZero++;
        if([[[UIApplication sharedApplication] delegate] window].safeAreaInsets.right == 0.0)iNumberSafeInsetsEqualZero++;
        if([[[UIApplication sharedApplication] delegate] window].safeAreaInsets.bottom == 0.0)iNumberSafeInsetsEqualZero++;
        if([[[UIApplication sharedApplication] delegate] window].safeAreaInsets.left == 0.0)iNumberSafeInsetsEqualZero++;

        return iNumberSafeInsetsEqualZero <= 2;

    }

    return  NO;

}

其他一些帖子都没用。例如，竖屏模式下“通话状态栏”(绿色栏)的iPhone 6S就有一个很大的顶部安全插件。在我的代码中，所有的情况都被占用(即使设备以纵向或横向启动)

仅在竖屏中，我使用视图框架的宽度和高度来检查:

override func viewDidLoad() {
    super.viewDidLoad()

    // iPhone Xr: -414 x 896
    // iPhone Xs Max: -414 x 896
    // iPhone X, Xs: -375 x 812

    if view.frame.width == 414 && view.frame.height == 896 || view.frame.width == 375 && view.frame.height == 812  {

        print("iPhone X")
    } else {

        print("not iPhone X")
    }

}

竖屏尺寸列在这里

更新

这个答案已经过时了，现在iPhone阵容中有更多的X系列，你要么必须在if-else中列出所有这些尺寸，要么检查设备是否有缺口会更容易。大约1.5年前，我从某个地方得到了这个答案/代码。如果我能链接到代码，我会的。

// 1. add an extension to UIDevice with this computed property
extension UIDevice {
    
    var hasTopNotch: Bool {
        if #available(iOS 11.0, tvOS 11.0, *) {
            return UIApplication.shared.delegate?.window??.safeAreaInsets.top ?? 0 > 20
        }
        return false
    }
} 

// 2. to use in any class
override func viewDidLoad() {
    super.viewDidLoad()

    if UIDevice.current.hasTopNotch {

        print("X series")

    } else {

        print("regular phone")
    }
}