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))"
    }
}

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

斯威夫特4

//首先通过定义一个可选的AnyObject来获取nsObject

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

//然后将对象转换为String，但要小心，你可能需要再次检查是否为nil

let version = nsObject as! String

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。

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

针对Swift 3.0更新

在Swift 3.0中，ns前缀已经没有了，一些属性/方法的名称已经更改为更Swifty。这是现在的样子:

extension Bundle {
    var releaseVersionNumber: String? {
        return infoDictionary?["CFBundleShortVersionString"] as? String
    }
    var buildVersionNumber: String? {
        return infoDictionary?["CFBundleVersion"] as? String
    }
}

Bundle.main.releaseVersionNumber
Bundle.main.buildVersionNumber

更新答案

I've been working with Frameworks a lot since my original answer, so I wanted to update my solution to something that is both simpler and much more useful in a multi-bundle environment: extension NSBundle { var releaseVersionNumber: String? { return self.infoDictionary?["CFBundleShortVersionString"] as? String } var buildVersionNumber: String? { return self.infoDictionary?["CFBundleVersion"] as? String } } Now this extension will be useful in apps to identify both the main bundle and any other included bundles (such as a shared framework for extension programming or third frameworks like AFNetworking), like so: NSBundle.mainBundle().releaseVersionNumber NSBundle.mainBundle().buildVersionNumber // or... NSBundle(URL: someURL)?.releaseVersionNumber NSBundle(URL: someURL)?.buildVersionNumber

原来的答案

I wanted to improve on some of the answers already posted. I wrote a class extension that can be added to your tool chain to handle this in a more logical fashion. extension NSBundle { class var applicationVersionNumber: String { if let version = NSBundle.mainBundle().infoDictionary?["CFBundleShortVersionString"] as? String { return version } return "Version Number Not Available" } class var applicationBuildNumber: String { if let build = NSBundle.mainBundle().infoDictionary?["CFBundleVersion"] as? String { return build } return "Build Number Not Available" } } So now you can access this easily by: let versionNumber = NSBundle.applicationVersionNumber