How can I detect if device is an iPad in iOS 8.3?

问题

We updated our SDK to iOS 8.3, and all of a sudden, our iPad detection method doesn't work properly:

+ (BOOL) isiPad
{
#ifdef UI_USER_INTERFACE_IDIOM
    return UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad;
#endif
    return NO;
}

the ifdef block is never entered, and so return NO; is always run. How do I detect if the device is an iPad without using UI_USER_INTERFACE_IDIOM()?

I'm using:

Xcode 6.3 (6D570)
iOS 8.2 (12D508) - Compiling with iOS 8.3 compiler
Deployment: Targeted Device Family: iPhone/iPad
Mac OS X: Yosemite (10.10.3)
Mac: MacBook Pro (MacBookPro11,3)

回答1:

In 8.2 UserInterfaceIdiom() is

#define UI_USER_INTERFACE_IDIOM() ([[UIDevice currentDevice] respondsToSelector:@selector(userInterfaceIdiom)] ? [[UIDevice currentDevice] userInterfaceIdiom] : UIUserInterfaceIdiomPhone)

In 8.3 UserInterfaceIdiom() is

static inline UIUserInterfaceIdiom UI_USER_INTERFACE_IDIOM() {
    return ([[UIDevice currentDevice] respondsToSelector:@selector(userInterfaceIdiom)] ?
            [[UIDevice currentDevice] userInterfaceIdiom] :
            UIUserInterfaceIdiomPhone);
}

So #ifdef UI_USER_INTERFACE_IDIOM is always false in 8.3

Note that the header says

The UI_USER_INTERFACE_IDIOM() function is provided for use when deploying to a version of the iOS less than 3.2. If the earliest version of iPhone/iOS that you will be deploying for is 3.2 or greater, you may use -[UIDevice userInterfaceIdiom] directly.

So suggest you refactor to

+ (BOOL) isiPad
{
    static BOOL isIPad = NO;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        isIPad = [[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad;
    });
    return isIPad;
}

来源：https://stackoverflow.com/questions/29608613/how-can-i-detect-if-device-is-an-ipad-in-ios-8-3

标签

ios

xcode

ipad

ios8.3