Ios 错误域=解析代码=209“操作无法完成

我安装了ParseStarter项目swift版本，并使用以下代码创建了一个新用户：

var user = PFUser()
...
user.signUpInBackgroundWithBlock...

然后，我再次运行该项目，发现以下错误：

2015-03-26 09:49:25.485项目[14768:199520][错误]：无效会话令牌代码：209，版本：1.7.0 2015-03-26 09:49:25.489 ParseStarter项目[14768:199521][Error]：最终未能运行命令，错误为：Error Domain=Parse Code=209操作无法完成。Parse Error 209.UserInfo=0x7fcda3cb6680{Error=invalid session token，Code=209}

---

我做错了什么？？？

我以为获取当前用户也会执行登录，但它不会。 所以问题是我试图保存一个对象而不执行登录

func login() {
    var username = username from UI or key store
    var password = password from UI or key store
    if let currentUser = PFUser.currentUser() {
        println("current user is \(currentUser.username)")
        username = currentUser.username
    }
    PFUser.logInWithUsernameInBackground(username, password:password) {
        (user: PFUser!, error: NSError!) -> Void in
        if user != nil {
            println("successful login with \(user.username)")
            self.saveSomething()
        } else {
            println("failed login with \(user.username)")
        }
    }

}

func saveSomething() {
    var gameScore = PFObject(className:"GameScore")
    gameScore["score"] = 1337
    gameScore["playerName"] = "Sean Plott"
    gameScore["cheatMode"] = false
    gameScore.saveInBackgroundWithBlock {
        (success: Bool, error: NSError!) -> Void in
        if (success) {
            println("The object has been saved")
        } else {
            println("There was a problem, check error.description")
        }

    }
}

如果用户未登录，PFUser.currentUser将返回nil。您只需要在为nil的情况下执行登录，并在if语句中添加else块。