Swift 5作为UIApplication扩展

extension UIApplication {
    static var release: String {
        return Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! String? ?? "x.x"
    }
    static var build: String {
        return Bundle.main.object(forInfoDictionaryKey: "CFBundleVersion") as! String? ?? "x"
    }
    static var version: String {
        return "\(release).\(build)"
    }
}

使用示例:

print("release: \(UIApplication.release)")
print("build: \(UIApplication.build)")
print("version: \(UIApplication.version)")

针对Swift 4.0

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

Swift 5更新

这是一个函数，我使用来决定是否显示“应用程序更新”页面或不。它返回版本号，我正在将其转换为Int类型:

if let version: String = Bundle.main.infoDictionary?["CFBundleVersion"] as? String {
        guard let intVersion = Int(version) else { return }
        
        if UserDefaults.standard.integer(forKey: "lastVersion") < intVersion {
            print("need to show popup")
        } else {
            print("Don't need to show popup")
        }
        
        UserDefaults.standard.set(intVersion, forKey: "lastVersion")
    }

如果以前从未使用过，它将返回0，小于当前版本号。若要不向新用户显示这样的屏幕，只需在首次登录后或登录完成时添加构建号。

看过文档后，我认为以下内容更清晰:

let version = 
NSBundle.mainBundle().objectForInfoDictionaryKey("CFBundleShortVersionString") 
as? String

来源: 使用此方法优于其他访问方法，因为它在键可用时返回键的本地化值。

if let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String {
            self.lblAppVersionValue.text = version
        }

Xcode 9.4.1 Swift 4.1

注意，使用localizedInfoDictionary来获取包显示名称的正确语言版本。

var displayName: String?
var version: String?
var build: String?

override func viewDidLoad() {
    super.viewDidLoad()

    // Get display name, version and build

    if let displayName = Bundle.main.localizedInfoDictionary?["CFBundleDisplayName"] as? String {
        self.displayName = displayName
    }
    if let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String {
        self.version = version
    }
    if let build = Bundle.main.infoDictionary?["CFBundleVersion"] as? String {
        self.build = build
    }
}