如何在iPhone5和iPhone6上更改UIImageView的大小？

Question

I have an image to display in my app. I want to set the size of the image on iPhone6 to 169pt & on iPhone5 set it 120pt. I know there is a size class on iOS8. But how can I set different sizes for different iPhones on it. I can only distinguish between iPad & iphone portrait/landscape in size classes & can not distinguish iPhone 5 from iPhone6

Answer 1

Have you considered using AutoLayout? It's a constraint-resolver based layout system that will make your views responsive, and it's Apple's preferred method starting in iOS7. Docs are here:

https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/AutolayoutPG/Introduction/Introduction.html

And a great tutorial here:

http://www.raywenderlich.com/50317/beginning-auto-layout-tutorial-in-ios-7-part-1

AutoLayout is a far more robust method for keeping your views responsive even as Apple adds new UI idioms and sizes (like the Apple Watch). Imperative sizing code will quickly become fragile as the number of sizes to support increases.

Answer 2

Just pulled this from one of my projects. It shows the logic I use for working out what device the user is using

#define IS_IPAD (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
#define IS_IPHONE (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
#define IS_IPHONE_5 (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 568.0)
#define IS_IPHONE_6 (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 667.0)
#define IS_IPHONE_6PLUS (IS_IPHONE && [[UIScreen mainScreen] nativeScale] == 3.0f)
#define IS_IPHONE_6_PLUS (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 736.0)
#define IS_RETINA ([[UIScreen mainScreen] scale] == 2.0)