NickName:Greg Ask DateTime:2011-08-28T04:51:22

what is the code to detect whether ios app running in iPhone, iPhone Retina display, or iPad?

Background:

for my iPhone application I have defined in XCode target/summary page the specific images for: iPhone launch image, iPhone retina display launch image, iPad portrait & iPad landscape.
in the main view there is a UIImageView subview I use for the background image - currently I'm specifying this in XCode (not programmatically) by selecting the image I use for the iPhone launch image.

So I'm asking how to tell which one I'm running within so that in the viewDidLoad I can load the appropriate resolution background image. Then there should be a seamless transition between the background image for app startup, and the background of the app main screen once it's started.

Copyright Notice：Content Author:「Greg」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/7217277/what-is-the-code-to-detect-whether-ios-app-running-in-iphone-iphone-retina-disp

Answers

omz 2011-08-27T21:04:03

You can use [[UIDevice currentDevice] userInterfaceIdiom] to determine whether you're running on an iPhone/iPod touch or an iPad.\n\nThere's often no need to determine directly whether you're on a retina display because UIImage handles that automatically when you use imageNamed and append \"@2x\" to your high resolution image file names (see Supporting High-Resolution Screens in the Drawing and Printing Guide for iOS).\n\nIf you really need to know which resolution the screen has, use UIScreen's scale method.",

Luke 2011-08-28T20:22:24

Here's 2 useful class methods that I use, which directly answers your question - which you may want to use further down the line:\n\n+(BOOL)isPad\n{\n#ifdef UI_USER_INTERFACE_IDIOM\n return UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad;\n#endif\n return NO;\n}\n\n+(BOOL)hasRetinaDisplay\n{\n // checks for iPhone 4. will return a false positive on iPads, so use the above function in conjunction with this to determine if it's a 3GS or below, or an iPhone 4.\n if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] && [[UIScreen mainScreen] scale] == 2)\n return YES;\n else\n return NO;\n}\n",

Masterfego 2015-03-16T14:53:54

For Swift Solution:\n\n if (UIDevice.currentDevice().userInterfaceIdiom == UIUserInterfaceIdiom.Pad) \n {\n // Ipad\n }\n else \n {\n // Iphone\n }\n",

justin 2011-08-27T20:54:01

see @interface UIDevice\n\nas well as the documentation at -[UIImage scale] (although there are better resources, which will likely be posted).",