对于Swift 5.0:

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

EDIT

Swift 4.2更新

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

EDIT

正如@azdev在Xcode的新版本上指出的那样，你会得到一个编译错误，尝试我以前的解决方案，要解决这个问题，只需编辑它，建议使用一个打开包字典!

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

最后编辑

使用与Objective-C中相同的逻辑，但有一些小的变化

//First get the nsObject by defining as an optional anyObject
let nsObject: AnyObject? = NSBundle.mainBundle().infoDictionary["CFBundleShortVersionString"]

//Then just cast the object as a String, but be careful, you may want to double check for nil
let version = nsObject as! String

我知道这个问题已经有人回答了，但我个人认为这个问题更清晰一些:

斯威夫特3.0:

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

斯威夫特< 2.3

if let version = NSBundle.mainBundle().infoDictionary?["CFBundleShortVersionString"] as? String {
    self.labelVersion.text = version
}

这样，if let版本就负责条件处理(在我的例子中设置标签文本)，如果infoDictionary或CFBundleShortVersionString为nil，则可选的展开将导致代码被跳过。

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。

2022年，Swift 5

extension Bundle {
    public var appName: String           { getInfo("CFBundleName")  }
    public var displayName: String       { getInfo("CFBundleDisplayName")}
    public var language: String          { getInfo("CFBundleDevelopmentRegion")}
    public var identifier: String        { getInfo("CFBundleIdentifier")}
    public var copyright: String         { getInfo("NSHumanReadableCopyright").replacingOccurrences(of: "\\\\n", with: "\n") }
    
    public var appBuild: String          { getInfo("CFBundleVersion") }
    public var appVersionLong: String    { getInfo("CFBundleShortVersionString") }
    //public var appVersionShort: String { getInfo("CFBundleShortVersion") }
    
    fileprivate func getInfo(_ str: String) -> String { infoDictionary?[str] as? String ?? "⚠️" }
}

用法(SwiftUI样本):

    Text("Ver: \(Bundle.main.appVersionLong) (\(Bundle.main.appBuild)) ")
    
    Text(Bundle.main.copyright)
        .font(.system(size: 10, weight: .thin))
        .multilineTextAlignment(.center)

奖励:版权支持\n符号!

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。