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

斯威夫特4

func getAppVersion() -> String {
    return "\(Bundle.main.infoDictionary!["CFBundleShortVersionString"] ?? "")"
}

Bundle.main.infoDictionary！[“CFBundleShortVersionString”]

快速旧语法

let appVer: AnyObject? = NSBundle.mainBundle().infoDictionary!["CFBundleShortVersionString"]

我也知道这个问题已经有了答案，但我总结了之前的答案:

(*)扩展更新

extension Bundle {
    var releaseVersionNumber: String? {
        return infoDictionary?["CFBundleShortVersionString"] as? String
    }
    var buildVersionNumber: String? {
        return infoDictionary?["CFBundleVersion"] as? String
    }
    var releaseVersionNumberPretty: String {
        return "v\(releaseVersionNumber ?? "1.0.0")"
    }
}

用法:

someLabel.text = Bundle.main.releaseVersionNumberPretty

@Deprecated:旧答案

斯威夫特3.1:

class func getVersion() -> String {
    guard let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String else {
        return "no version info"
    }
    return version
}

对于旧版本:

class func getVersion() -> String {
    if let version = NSBundle.mainBundle().infoDictionary?["CFBundleShortVersionString"] as? String {
        return version
    }
    return "no version info"
}

如果你想设置标签文本或者想在其他地方使用;

self.labelVersion.text = getVersion()

对于Swift 3.0 NSBundle不工作，下面的代码工作完美。

let versionNumberString =
      Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString")
          as! String

对于版本号，它是:

let buildNumberString =
      Bundle.main.object(forInfoDictionaryKey: "CFBundleVersion")
          as! String

令人困惑的'CFBundleVersion'是在Xcode General->Identity中输入的构建号。

针对Swift 2.0

//First get the nsObject by defining as an optional anyObject

let nsObject: AnyObject? = NSBundle.mainBundle().infoDictionary!["CFBundleShortVersionString"]
let version = nsObject as! String

以下是Swift 3.2的更新版本:

extension UIApplication
{
    static var appVersion:String
    {
        if let appVersion = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString")
        {
            return "\(appVersion)"
        }
        return ""
    }

    static var buildNumber:String
    {
        if let buildNum = Bundle.main.object(forInfoDictionaryKey: kCFBundleVersionKey as String)
        {
            return "\(buildNum)"
        }
        return ""
    }

    static var versionString:String
    {
        return "\(appVersion).\(buildNumber)"
    }
}