本来这是QQ群里一个朋友的问题，网上查了一下，现在将方法大概整理一下，以便于需要的朋友使用。当然，使用
UIDevice类，也可以简单的获得到底当前平台是iphone 还是itouch,但是你所获得的信息也就仅限于此了，如果想获得更多的
硬件平台信息呢？使用sysctlbyname，即可。
获取当前的平台信息，需要查询hw.machine 值，返回值为以下字符串：
iPhone1,1 (iphone一代)
iPhone1,2 (iphone 3G)
iPhone2,1 (iphone 3Gs)
iPhone3,1 (Iphone 4)
iPod1,1 (iPod Touch 1代)
iPod2,1 (iPod Touch 2代)
iPod3,1 (iPod Touch 3代)
i386 (模拟器)
使用方法：
UIDeviceHardware *h=[[UIDeviceHardware alloc] init];
[self setDeviceModel:[h platformString]];
[h release];
UIDeviceHardware.h 头文件
//
// UIDeviceHardware.h
//
// Used to determine EXACT version of device software is running on.
#import <Foundation/Foundation.h>
@interface UIDeviceHardware : NSObject
- (NSString *) platform;
- (NSString *) platformString;
@end
UIDeviceHardware.m 实现文件
//
// UIDeviceHardware.m
//
// Used to determine EXACT version of device software is running on.
#import "UIDeviceHardware.h"
#include <sys/types.h>
#include <sys/sysctl.h>
@implementation UIDeviceHardware
- (NSString *) platform{
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];
free(machine);
return platform;
}
- (NSString *) platformString{
NSString *platform = [self platform];
if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 1G";
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:@"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:@"i386"]) return @"iPhone Simulator";
return platform;
}
@end