相关疑难解决方法(0)

我怎样才能检测到第一次发布

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  // if very first launch than perform actionA
  // else perform actionB
}

方法？

我想通过按下"感觉幸运"按钮切换到第二个视图.当我试用我的模拟器并按下它时,它就会变成黑屏.我怎么能解决这个问题？

@IBAction func FeelingLuckyPress(sender: UIButton) {

    let secondViewController:SecondViewController = SecondViewController()

    self.presentViewController(secondViewController, animated: true, completion: nil)
}