改变状态栏颜色为白字黑底：
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
UIApplication.sharedApplication().setStatusBarStyle(UIStatusBarStyle.LightContent, animated: false)
}
另外要在info里面加上View controller-based status bar appearance 设置为 NO
原文：http://www.cnblogs.com/helloandroid/p/4316359.html