if(UI_USER_INTERFACE_IDIOM () == UIUserInterfaceIdiom.pad)
 {
            print("This is iPad")
 }else if (UI_USER_INTERFACE_IDIOM () == UIUserInterfaceIdiom.phone)
 {
            print("This is iPhone");
  }

UI_USER_INTERFACE_IDIOM()只返回iPad如果应用程序是iPad或通用。如果这是一款运行在iPad上的iPhone应用，那么它就不会这么做。所以你应该检查模型。

为什么这么复杂?我就是这么做的…

斯威夫特4:

var iPad : Bool {
    return UIDevice.current.model.contains("iPad")
}

这样你就可以说if iPad {}

你可以检查rangeOfString来查看单词iPad是否像这样存在。

NSString *deviceModel = (NSString*)[UIDevice currentDevice].model;

if ([deviceModel rangeOfString:@"iPad"].location != NSNotFound)  {
NSLog(@"I am an iPad");
} else {
NSLog(@"I am not an iPad");
}

if(UI_USER_INTERFACE_IDIOM () == UIUserInterfaceIdiom.pad)
 {
            print("This is iPad")
 }else if (UI_USER_INTERFACE_IDIOM () == UIUserInterfaceIdiom.phone)
 {
            print("This is iPhone");
  }

在Swift 4.2和Xcode 10中

if UIDevice().userInterfaceIdiom == .phone {
    //This is iPhone
} else if UIDevice().userInterfaceIdiom == .pad { 
    //This is iPad
} else if UIDevice().userInterfaceIdiom == .tv {
    //This is Apple TV
}

如果你想检测特定的设备

let screenHeight = UIScreen.main.bounds.size.height
if UIDevice().userInterfaceIdiom == .phone {
    if (screenHeight >= 667) {
        print("iPhone 6 and later")
    } else if (screenHeight == 568) {
        print("SE, 5C, 5S")
    } else if(screenHeight<=480){
        print("4S")
    }
} else if UIDevice().userInterfaceIdiom == .pad { 
    //This is iPad
}