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

对于任何感兴趣的人，在github上有一个漂亮而整洁的库叫做SwifterSwift，它也有完整的swift版本文档(参见swifterswift.com)。

使用这个库，读取应用版本和构建号就像这样简单:

import SwifterSwift

let buildNumber = SwifterSwift.appBuild
let version = SwifterSwift.appVersion

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

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"]

Bundle+Extension.swift (SwiftUI, swift 5, Xcode 11)

我结合了一些答案的想法，并扩展了一点:

一个SwiftUI的例子 如果Info.plist中缺少键，则显示警告三角形表情符号(而不是使应用程序崩溃)

进口的基础

extension Bundle {
    
    public var appVersionShort: String {
        if let result = infoDictionary?["CFBundleShortVersionString"] as? String {
            return result
        } else {
            return "⚠️"
        }
    }
    public var appVersionLong: String {
        if let result = infoDictionary?["CFBundleVersion"] as? String {
            return result
        } else {
            return "⚠️"
        }
    }
    public var appName: String {
        if let result = infoDictionary?["CFBundleName"] as? String {
            return result
        } else {
            return "⚠️"
        }
    }
}

SwiftUI实例使用

VStack {

     Text("Version: \(Bundle.main.appVersionShort!) (\(Bundle.main.appVersionLong!))")
                    .font(.subheadline)
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
}

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)")