学步园

方法一：

//***宏定义

#define iPhone5 ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size) : NO)

然后：
if（iPhone5）{
//***具体操作
}else{
 
//***具体操作

}

方法二：

还有做适配，代码中不要写320和480什么的初始化坐标，要用屏幕高度和宽度初始化
#define Screen_height   [[UIScreen mainScreen] bounds].size.height
#define Screen_width    [[UIScreen mainScreen] bounds].size.width 

方法三：

+ (NSString*)deviceString
{
    // 需要#import "sys/utsname.h"
    struct utsname systemInfo;
    uname(&systemInfo);
    NSString *deviceString = [NSString stringWithCString:systemInfo.machine encoding:NSUTF8StringEncoding];
     
    if ([deviceString isEqualToString:@"iPhone1,1"])    return @"iPhone 1G";
    if ([deviceString isEqualToString:@"iPhone1,2"])    return @"iPhone 3G";
    if ([deviceString isEqualToString:@"iPhone2,1"])    return @"iPhone 3GS";
    if ([deviceString isEqualToString:@"iPhone3,1"])    return @"iPhone 4";
    if ([deviceString isEqualToString:@"iPhone4,1"])    return @"iPhone 4S";
    if ([deviceString isEqualToString:@"iPhone5,2"])    return @"iPhone 5";
    if ([deviceString isEqualToString:@"iPhone3,2"])    return @"Verizon iPhone 4";
    if ([deviceString isEqualToString:@"iPod1,1"])      return @"iPod Touch 1G";
    if ([deviceString isEqualToString:@"iPod2,1"])      return @"iPod Touch 2G";
    if ([deviceString isEqualToString:@"iPod3,1"])      return @"iPod Touch 3G";
    if ([deviceString isEqualToString:@"iPod4,1"])      return @"iPod Touch 4G";
    if ([deviceString isEqualToString:@"iPad1,1"])      return @"iPad";
    if ([deviceString isEqualToString:@"iPad2,1"])      return @"iPad 2 (WiFi)";
    if ([deviceString isEqualToString:@"iPad2,2"])      return @"iPad 2 (GSM)";
    if ([deviceString isEqualToString:@"iPad2,3"])      return @"iPad 2 (CDMA)";
    if ([deviceString isEqualToString:@"i386"])         return @"Simulator";
    if ([deviceString isEqualToString:@"x86_64"])       return @"Simulator";
    NSLog(@"NOTE: Unknown device type: %@", deviceString);
    return deviceString;
}
from:http://www.devdiv.com/forum.php?mod=viewthread&tid=122890&page=1#pid710813