问题：
storyboard新建viewcontroller后，无法关联第一控制器，显示黑屏，console显示
Failed to instantiate the default view controller for UIMainStoryboardFile ‘Main‘ - perhaps the designated entry point is not set?
解决办法：
In your story board file select the viewController you want to assign as first controller and check on is initial View Controller check the image.
新建viewcontroller需要关联并分配给第一控制器，并初始化视图控制器。
如下图所示：
swift学习——点点滴滴——2~storyboard新建viewcontroller
原文：http://my.oschina.net/meowmeow/blog/339976