有7.0或6.0.3这样的版本，所以我们可以简单地将版本转换为数字进行比较。如果版本类似于7.0，只需追加另一个”。0”，然后取它的数值。

 int version;
 NSString* iosVersion=[[UIDevice currentDevice] systemVersion];
 NSArray* components=[iosVersion componentsSeparatedByString:@"."];
 if ([components count]==2) {
    iosVersion=[NSString stringWithFormat:@"%@.0",iosVersion];

 }
 iosVersion=[iosVersion stringByReplacingOccurrencesOfString:@"." withString:@""];
 version=[iosVersion integerValue];

为0

  if (version==600) {
    // Do something
  }

为7.0

 if (version==700) {
   // Do something
 }

使用swift Forget [[UIDevice currentDevice] systemVersion]和NSFoundationVersionNumber检查系统版本的新方法。

我们可以使用NSProcessInfo -isOperatingSystemAtLeastVersion

     import Foundation

     let yosemite = NSOperatingSystemVersion(majorVersion: 10, minorVersion: 10, patchVersion: 0)
     NSProcessInfo().isOperatingSystemAtLeastVersion(yosemite) // false

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)

然后添加if条件，如下所示:-

if(SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"10.0")) {
   //Your code
}       

/*
 *  System Versioning Preprocessor Macros
 */ 

#define SYSTEM_VERSION_EQUAL_TO(v)                  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedSame)
#define SYSTEM_VERSION_GREATER_THAN(v)              ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedDescending)
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN(v)                 ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v)     ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedDescending)

/*
 *  Usage
 */ 

if (SYSTEM_VERSION_LESS_THAN(@"4.0")) {
    ...
}

if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"3.1.1")) {
    ...
}

在您的项目中添加以下Swift代码，并轻松访问iOS版本和设备等信息。

class DeviceInfo: NSObject {

    struct ScreenSize
    {
        static let SCREEN_WIDTH = UIScreen.main.bounds.size.width
        static let SCREEN_HEIGHT = UIScreen.main.bounds.size.height
        static let SCREEN_MAX_LENGTH = max(ScreenSize.SCREEN_WIDTH, ScreenSize.SCREEN_HEIGHT)
        static let SCREEN_MIN_LENGTH = min(ScreenSize.SCREEN_WIDTH, ScreenSize.SCREEN_HEIGHT)
    }

    struct DeviceType
    {
        static let IS_IPHONE_4_OR_LESS =  UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH < 568.0
        static let IS_IPHONE_5 = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 568.0
        static let IS_IPHONE_6 = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH >= 667.0
        static let IS_IPHONE_6P = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 736.0
        static let IS_IPHONE_X = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 812.0
        static let IS_IPAD      = UIDevice.current.userInterfaceIdiom == .pad && ScreenSize.SCREEN_MAX_LENGTH == 1024.0
        static let IS_IPAD_PRO  = UIDevice.current.userInterfaceIdiom == .pad && ScreenSize.SCREEN_MAX_LENGTH == 1366.0
    }

    struct VersionType{
        static let SYS_VERSION_FLOAT = (UIDevice.current.systemVersion as NSString).floatValue
        static let iOS7 = (VersionType.SYS_VERSION_FLOAT < 8.0 && VersionType.SYS_VERSION_FLOAT >= 7.0)
        static let iOS8 = (VersionType.SYS_VERSION_FLOAT >= 8.0 && VersionType.SYS_VERSION_FLOAT < 9.0)
        static let iOS9 = (VersionType.SYS_VERSION_FLOAT >= 9.0 && VersionType.SYS_VERSION_FLOAT < 10.0)
        static let iOS10 = (VersionType.SYS_VERSION_FLOAT >= 9.0 && VersionType.SYS_VERSION_FLOAT < 11.0)
    }
}

作为yasimturks解决方案的一种变体，我定义了一个函数和一些枚举值，而不是五个宏。我觉得它更优雅，但那是个人品味的问题。

用法:

if (systemVersion(LessThan, @"5.0")) ...

. h文件:

typedef enum {
  LessThan,
  LessOrEqual,
  Equal,
  GreaterOrEqual,
  GreaterThan,
  NotEqual
} Comparison;

BOOL systemVersion(Comparison test, NSString* version);

m文件:

BOOL systemVersion(Comparison test, NSString* version) {
  NSComparisonResult result = [[[UIDevice currentDevice] systemVersion] compare: version options: NSNumericSearch];
  switch (test) {
    case LessThan:       return result == NSOrderedAscending;
    case LessOrEqual:    return result != NSOrderedDescending;
    case Equal:          return result == NSOrderedSame;
    case GreaterOrEqual: return result != NSOrderedAscending;
    case GreaterThan:    return result == NSOrderedDescending;
    case NotEqual:       return result != NSOrderedSame;
  }
}

你应该在名称中添加应用程序的前缀，尤其是比较类型。