调用[[UIDevice currentDevice] userInterfaceIdiom]==UIUserInterfaceIdiomPad判断设备

将模拟器改为Ipad时，调用[[UIDevice currentDevice] userInterfaceIdiom]==UIUserInterfaceIdiomPad判断设备是否为Ipad，但程序并未做出正确的判断，后来做出如下设置：

PROJECT->Build Settings->Deployment->Targeted Device Family->iPhone/iPad

再次调试程序，成功识别出设备