#define ScreenWidth  ([[UIScreen mainScreen] bounds].size.width)
#define ScreenHeight ([[UIScreen mainScreen] bounds].size.height)
 
#define iOS8 ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
#define iOS7 ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)
#define iOS6 ([[[UIDevice currentDevice] systemVersion] floatValue] >= 6.0)
 
#define isPad   (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad   ? YES : NO)
#define isPhone (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone ? YES : NO)
#define isRetina ([[UIScreen mainScreen] scale] > 1 ? YES : NO)

-(void)getIOSVersion {
// #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 50000 //此方法和编译器相关
// quanju.iOSVersion=1;
// #endif 
    float version = [[[UIDevice currentDevice] systemVersion] floatValue]; 
    if (version >= 5.0) { 
        quanju.iOSVersion=1;//定义全局变量标记ios版本
    } 
}

-(void)getIOSModel{
    CGSize sizeToRequest; 
    if([[[UIDevicecurrentDevice] model] rangeOfString:@"iPad"].location== 0) 
        sizeToRequest = CGSizeMake(748, 110); 
    else 
        sizeToRequest = CGSizeMake(320, 48); 
}

//下面是ios内其他相关信息的判断方法

获取进程信息和设备信息（包括设备类型，序列号，ios版本等）
[[NSProcessInfo processInfo] globallyUniqueString],
[[NSProcessInfo processInfo] hostName],
[[NSProcessInfo processInfo] operatingSystemName],
[[NSProcessInfo processInfo] operatingSystemVersionString],
[[NSProcessInfo processInfo] physicalMemory],
[[NSProcessInfo processInfo] processName]);
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[UIDevice currentDevice].uniqueIdentifier,
[UIDevice currentDevice].name,
[UIDevice currentDevice].systemName,
[UIDevice currentDevice].systemVersion,
[UIDevice currentDevice].model,
[UIDevice currentDevice].localizedModel,
[UIDevice currentDevice].batteryLevel
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NSLog([[UIDevice currentDevice] name]); // Name of the phone as named by user
NSLog([[UIDevice currentDevice] uniqueIdentifier]); // A GUID like string
NSLog([[UIDevice currentDevice] systemName]); // "iPhone OS"
NSLog([[UIDevice currentDevice] systemVersion]); // "2.2.1"
NSLog([[UIDevice currentDevice] model]); // "iPhone" on both devices
NSLog([[UIDevice currentDevice] localizedModel]); // "iPhone" on both devices