1.导入头文件
#import "sys/utsname.h"
2.获取原理：获取当前设备的型号标识符，根据型号标识符对应的手机型号来判断当前设备型号。
型号标识符与手机型号的对应关系见：https://www.theiphonewiki.com/wiki/Models#iPhone
3.代码实例（最好是封装到工具类中）。
+ (NSString *)iphoneType {
struct utsname systemInfo;
uname(&systemInfo);
//型号标识符
NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding];
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";
if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";
if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5";
if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5";
if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c";
if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c";
if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s";
if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s";
if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 Plus";
if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6";
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";
if ([platform isEqualToString:@"iPhone9,3"]) return @"iPhone 7";
if ([platform isEqualToString:@"iPhone9,2"]) return @"iPhone 7 Plus";
if ([platform isEqualToString:@"iPhone9,4"]) return @"iPhone 7 Plus";
if ([platform isEqualToString:@"iPhone10,1"]) return @"iPhone 8";
if ([platform isEqualToString:@"iPhone10,4"]) return @"iPhone 8";
if ([platform isEqualToString:@"iPhone10,2"]) return @"iPhone 8 Plus";
if ([platform isEqualToString:@"iPhone10,5"]) return @"iPhone 8 Plus";
if ([platform isEqualToString:@"iPhone10,3"]) return @"iPhone X";
if ([platform isEqualToString:@"iPhone10,6"]) return @"iPhone X";
if ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G";
if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,7"]) return@"iPad Mini 3";
if ([platform isEqualToString:@"iPad4,8"]) return@"iPad Mini 3";
if ([platform isEqualToString:@"iPad4,9"]) return@"iPad Mini 3";
if ([platform isEqualToString:@"iPad5,1"]) return@"iPad Mini 4";
if ([platform isEqualToString:@"iPad5,2"]) return@"iPad Mini 4";
if ([platform isEqualToString:@"iPad5,3"]) return @"iPad Air 2";
if ([platform isEqualToString:@"iPad5,4"]) return @"iPad Air 2";
if ([platform isEqualToString:@"iPad6,3"]) return @"iPad Pro 9.7";
if ([platform isEqualToString:@"iPad6,4"]) return @"iPad Pro 9.7";
if ([platform isEqualToString:@"iPad6,7"]) return @"iPad Pro 12.9";
if ([platform isEqualToString:@"iPad6,8"]) return @"iPad Pro 12.9";
if ([platform isEqualToString:@"iPad6,11"]) return @"iPad 5";
if ([platform isEqualToString:@"iPad6,12"]) return @"iPad 5";
if ([platform isEqualToString:@"iPad7,1"]) return @"iPad Pro 12.9 2nd";
if ([platform isEqualToString:@"iPad7,2"]) return @"iPad Pro 12.9 2nd";
if ([platform isEqualToString:@"iPad7,3"]) return @"iPad Pro 10.5";
if ([platform isEqualToString:@"iPad7,4"]) return @"iPad Pro 10.5";
if ([platform isEqualToString:@"iPad7,5"]) return @"iPad 6";
if ([platform isEqualToString:@"iPad7,6"]) return @"iPad 6";
if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator";
if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator";
return platform;
}