我正在发现 XCode 和 iOS 开发。深入研究 iOS 文档，我尝试下载并运行一些编程示例。例如，我将使用 AccelerometerGraph。如果我下载代码并尝试编译，我会收到一条错误消息，并且我意识到导航面板告诉我：Base SDK Missing。在摆弄之后（stackoverflow 上的现有答案是指 Xcode 3.2 答案，这不起作用）我想我应该去“编辑器>验证设置...”并接受更改。它“似乎”工作，（如“缺少 SDK”消息消失，我可以编译）但我想知道我是否缺少更基本的东西。另外，我认为如果有这样一个根本性的变化，将它放在其中一个问题中会很有用。
谢谢P。
Go to the project settings and choose "Latest SDK" for the SDK option and that should fix your projects.
And if you want to be super helpful, file a bug with Apple (at http://bugreporter.apple.com) and tell them to update these outdated sample projects to use the latest SDK's if possible.
Not missing something more fundamental. Apple's sample projects have a variety of vintages. Mostly they compile and link under the current versions of Xcode and friends. Some need to be brought up to date. What you found was one that was originally set up for an obsolete version of the SDK and it compiles and links fine with one that was automagically found on your system when you updated it.