通常在设置赏金后我会找到答案.

Typical that after setting a bounty I find the answer.

问题出在我的故事板文件中，而不是我的代码中:

The issue was in my storyboard file, not my code:

最初，我在转场后的视图属性中有这个:

Originally, I had this in the properties of my view after the segue:

把它改成这样会使 SKView 填满整个屏幕:

And changing it to this made the SKView fill the entire screen:

显然在某些时候 Xcode 发生了变化，因此无论出于何种原因，自动"不再填满屏幕.

Clearly at some point Xcode changed so that 'Automatic' no longer filled the screen for whatever reason.

更多说明，当您打开故事板文件时，单击/选择要调整的视图控制器，在属性检查器下，有一个用于演示的选项，您可以在其中选择全屏"属性.

For more clarification, when you open the storyboard file, click/select the view controller that you want to adjust, under the Attributes Inspector, there is an option for Presentation where you can select the "Full Screen" attribute.