iOS Tips---Swift to determine iOS version and adaptation

operatingSystemVersion

为了更复杂的版本比较，operatingSystemVersion能够被直接检查。将它和Swift模式比较和switch语句组合，可以使得代码更简洁。




let os = NSProcessInfo().operatingSystemVersion

switch (os.majorVersion, os.minorVersion, os.patchVersion) { case (8, _, _):      println( "iOS >= 8.0.0" ) case (7, 0, _):      println( "iOS >= 7.0.0, < 7.1.0" ) case (7, _, _):      println( "iOS >= 7.1.0, < 8.0.0" ) default :      println( "iOS < 7.0.0" )

}













Uidevice systemversion

Unfortunately, the new Nsprocessinfo API is not particularly useful at this time because they do not take effect on iOS 7.

As an alternative, you can use the Systemversion property uidevice to check:

switch UIDevice.currentDevice().systemVersion.compare( "8.0.0" , options: NSStringCompareOptions.NumericSearch) { case .OrderedSame, .OrderedDescending:      println( "iOS >= 8.0" ) case .OrderedAscending:      println( "iOS < 8.0" ) }

Adaptation screen

switch uidevice. Currentdevice (). systemversion . Compare ("7.0.0", Options: nsstringcompareoptions. Numericsearch) {

case . Orderedsame,. Ordereddescending:

println("IOS >= 7.0")

self. Edgesforextendedlayout = Uirectedge . None

self. automaticallyadjustsscrollviewinsets = false

case . Orderedascending:

println("IOS < 7.0")

}

iOS Tips---Swift to determine iOS version and adaptation