导航到目标并转到 Build Phases 并将 UIKit 添加到 Link Binary With Libraries.

Navigate to the target and go to Build Phases and add UIKit to Link Binary With Libraries.

从评论到这篇文章:

MonkeyBusiness:很抱歉浪费您的时间.我已将该项目设置为 MacOS 而不是 iOS.如您所见，我是 Apple 和 iOS 的新手.

MonkeyBusiness: Sorry to waste your time. I had set the project up as MacOS rather than iOS. I'm new to Apple and iOS as you can see.