iOS 8自定义键盘：在某些情况下，view.DidLayoutSubviews中的self.inputView.bounds仍为{0,0}，{0,0}

I'm creating an iOS 8 Custom Keyboard extension primarily using AutoLayout in my XIB. The last step of layout is adding the keyboard keys programmatically. To do this, I I'm creating an iOS 8 Custom Keyboard extension