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"
}

我在我的应用程序中使用这个。截至2012年12月。

- (NSString *) platformString {
    // Gets a string with the device model
    size_t size;  
    sysctlbyname("hw.machine", NULL, &size, NULL, 0);  
    char *machine = malloc(size);  
    sysctlbyname("hw.machine", machine, &size, NULL, 0);  
    NSString *platform = [NSString stringWithCString:machine encoding:NSUTF8StringEncoding];  
    free(machine); 

    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";
    if ([platform isEqualToString:@"iPhone3,2"])    return @"iPhone 4";
    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";
    if ([platform isEqualToString:@"iPhone5,2"])    return @"iPhone 5 (GSM+CDMA)";

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

    if ([platform isEqualToString:@"iPad1,1"])      return @"iPad";
    if ([platform isEqualToString:@"iPad1,2"])      return @"iPad 3G";
    if ([platform isEqualToString:@"iPad2,1"])      return @"iPad 2 (WiFi)";
    if ([platform isEqualToString:@"iPad2,2"])      return @"iPad 2";
    if ([platform isEqualToString:@"iPad2,3"])      return @"iPad 2 (CDMA)";
    if ([platform isEqualToString:@"iPad2,4"])      return @"iPad 2";
    if ([platform isEqualToString:@"iPad2,5"])      return @"iPad Mini (WiFi)";
    if ([platform isEqualToString:@"iPad2,6"])      return @"iPad Mini";
    if ([platform isEqualToString:@"iPad2,7"])      return @"iPad Mini (GSM+CDMA)";
    if ([platform isEqualToString:@"iPad3,1"])      return @"iPad 3 (WiFi)";
    if ([platform isEqualToString:@"iPad3,2"])      return @"iPad 3 (GSM+CDMA)";
    if ([platform isEqualToString:@"iPad3,3"])      return @"iPad 3";
    if ([platform isEqualToString:@"iPad3,4"])      return @"iPad 4 (WiFi)";
    if ([platform isEqualToString:@"iPad3,5"])      return @"iPad 4";
    if ([platform isEqualToString:@"iPad3,6"])      return @"iPad 4 (GSM+CDMA)";

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

    return platform;
}  

你可以在GitHub上查看GBDeviceInfo，也可以通过CocoaPods获得。它提供了简单的API来检测各种属性，支持所有最新的设备:

设备的家庭

[GBDeviceInfo deviceDetails]。family == GBDeviceFamilyiPhone;

设备模型

[GBDeviceInfo deviceDetails]。model == GBDeviceModeliPhone6。

欲了解更多，请参阅Readme。

if([UIDevice currentDevice].userInterfaceIdiom==UIUserInterfaceIdiomPad) {
    //Device is ipad 
}else{
    //Device is iphone
}

更有用

#include <sys/types.h>
#include <sys/sysctl.h>

@interface UIDevice(Hardware)

- (NSString *) platform;

- (BOOL)hasRetinaDisplay;

- (BOOL)hasMultitasking;

- (BOOL)hasCamera;

@end

@implementation UIDevice(Hardware)

- (NSString *) platform{
    int mib[2];
size_t len;
char *machine;

mib[0] = CTL_HW;
mib[1] = HW_MACHINE;
sysctl(mib, 2, NULL, &len, NULL, 0);
machine = malloc(len);
sysctl(mib, 2, machine, &len, NULL, 0);

    NSString *platform = [NSString stringWithCString:machine encoding:NSASCIIStringEncoding];
    free(machine);
return platform;
}

- (BOOL)hasRetinaDisplay {
    NSString *platform = [self platform];
    BOOL ret = YES;
    if ([platform isEqualToString:@"iPhone1,1"]) {
        ret = NO;
    }
    else
        if ([platform isEqualToString:@"iPhone1,2"])    ret = NO;
    else 
        if ([platform isEqualToString:@"iPhone2,1"])    ret = NO;
    else 
        if ([platform isEqualToString:@"iPod1,1"])      ret = NO;
    else
        if ([platform isEqualToString:@"iPod2,1"])      ret = NO;
    else
        if ([platform isEqualToString:@"iPod3,1"])      ret = NO;
    return ret;
}

- (BOOL)hasMultitasking {
    if ([self respondsToSelector:@selector(isMultitaskingSupported)]) {
        return [self isMultitaskingSupported];
    }
    return NO;
}

- (BOOL)hasCamera {
   BOOL ret = NO;
   // check camera availability
   return ret;
}

@end

您可以读取属性

NSLog(@"platform %@, retita %@, multitasking %@", [[UIDevice currentDevice] platform], [[UIDevice currentDevice] hasRetinaDisplay] ? @"YES" : @"NO" , [[UIDevice currentDevice] hasMultitasking] ? @"YES" : @"NO");

请随意使用这个类(gist @ github)

代码已删除并重新定位到 https://gist.github.com/1323251

更新(01/14/11)

显然，这段代码现在有点过时了，但它肯定可以使用Brian Robbins提供的这个线程上的代码进行更新，其中包括更新模型的类似代码。谢谢你在这个帖子上的支持。