这是iOS 3.2的UIDevice的一部分，例如:

[UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad

有很多方法可以检查设备是否为iPad。这是我最喜欢的检查设备是否真的是iPad的方法:

if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad )
{
    return YES; /* Device is iPad */
}

我使用它的方式

#define IDIOM    UI_USER_INTERFACE_IDIOM()
#define IPAD     UIUserInterfaceIdiomPad

if ( IDIOM == IPAD ) {
    /* do something specifically for iPad. */
} else {
    /* do something specifically for iPhone or iPod touch. */
}   

其他的例子

if ( [(NSString*)[UIDevice currentDevice].model hasPrefix:@"iPad"] ) {
    return YES; /* Device is iPad */
}

#define IPAD     (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
if ( IPAD ) 
     return YES;

有关Swift解决方案，请参阅以下答案:https://stackoverflow.com/a/27517536/2057171

你也可以用这个

#define IPAD UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad
...
if (IPAD) {
   // iPad
} else {
   // iPhone / iPod Touch
}

对于最新版本的iOS，只需添加UITraitCollection:

extension UITraitCollection {

    var isIpad: Bool {
        return horizontalSizeClass == .regular && verticalSizeClass == .regular
    }
}

然后在UIViewController中检查:

if traitCollection.isIpad { ... }

斯威夫特的另一种方式:

//MARK: -  Device Check
let iPad = UIUserInterfaceIdiom.Pad
let iPhone = UIUserInterfaceIdiom.Phone
@available(iOS 9.0, *) /* AppleTV check is iOS9+ */
let TV = UIUserInterfaceIdiom.TV

extension UIDevice {
    static var type: UIUserInterfaceIdiom 
        { return UIDevice.currentDevice().userInterfaceIdiom }
}

用法:

if UIDevice.type == iPhone {
    //it's an iPhone!
}

if UIDevice.type == iPad {
    //it's an iPad!
}

if UIDevice.type == TV {
    //it's an TV!
}

注意:如果你的应用只针对iPhone设备，在iPhone兼容模式下运行的iPad将为以下语句返回false:

#define IPAD     UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad

检测实体iPad设备的正确方法是:

#define IS_IPAD_DEVICE      ([(NSString *)[UIDevice currentDevice].model hasPrefix:@"iPad"])