public var appVersionNumberString: String {
    get {
        return Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! String
    }
}

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)")

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

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。

Swift 4，有用的扩展包

import Foundation

public extension Bundle {

    public var shortVersion: String {
        if let result = infoDictionary?["CFBundleShortVersionString"] as? String {
            return result
        } else {
            assert(false)
            return ""
        }
    }

    public var buildVersion: String {
        if let result = infoDictionary?["CFBundleVersion"] as? String {
            return result
        } else {
            assert(false)
            return ""
        }
    }

    public var fullVersion: String {
        return "\(shortVersion)(\(buildVersion))"
    }
}

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"
    }
}