鉴于Swift一直在发展，我的回答(截至2015年8月):

let version = NSBundle.mainBundle().infoDictionary!["CFBundleVersion"] as! String

简单的实用函数返回应用程序版本为Int

func getAppVersion() -> Int {

        if let appVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String {

            let appVersionClean = appVersion.replacingOccurrences(of: ".", with: "", options: NSString.CompareOptions.literal, range:nil)

            if let appVersionNum = Int(appVersionClean) {
                return appVersionNum
            }
        }
        return 0
    }

Xcode 8, Swift 3:

let gAppVersion = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") ?? "0"
let gAppBuild = Bundle.main.object(forInfoDictionaryKey: "CFBundleVersion") ?? "0"

我为UIApplication创建了一个扩展。

extension UIApplication {
    static var appVersion: String {
        let versionNumber = Bundle.main.infoDictionary?[IdentifierConstants.InfoPlist.versionNumber] as? String
        let buildNumber = Bundle.main.infoDictionary?[IdentifierConstants.InfoPlist.buildNumber] as? String
        
        let formattedBuildNumber = buildNumber.map {
            return "(\($0))"
        }

        return [versionNumber,formattedBuildNumber].compactMap { $0 }.joined(separator: " ")
    }
}

enum Constants {
    enum InfoPlist {
        static let versionNumber = "CFBundleShortVersionString"
        static let buildNumber = "CFBundleVersion"
    }
}

斯威夫特4

//首先通过定义一个可选的AnyObject来获取nsObject

let nsObject: AnyObject? = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as AnyObject

//然后将对象转换为String，但要小心，你可能需要再次检查是否为nil

let version = nsObject as! String

针对Swift 4.0

let version = Bundle.main.infoDictionary!["CFBundleShortVersionString"]!
let build = Bundle.main.infoDictionary!["CFBundleVersion"]!