允许框架模块中的非模块化包含为YES!为我解决了同样的问题。

对我来说，解决方案是去目标->构建设置->允许框架模块中的非模块化包含切换到YES!

当我在一个项目中包含我自己的框架时，我就遇到了这个问题。修正了将sqlite3.h的所有导入都放在。m文件中，而不是公共的。h文件中。我认为其他库也会在Xcode中标记出类似的问题。

这是编译器预期的行为，有很好的理由。

I think the majority of people running into this issues is caused after they switch from Application Target to Framework Target and start adding C and Objective C headers into framework's umbrella header expecting it to have a same behaviour as application's Bridging Header, which behaves differently. The umbrella header is actually designated for mixed swift, obj-c framework and its purpose is exposing the APIs to the outer world that your framework has in objective-c or c. That means the headers we put there should be in the public scope.

它不应该被用作将不属于框架的Objective-C/C头文件暴露给框架swift代码的地方。因为在这种情况下，这些头文件也将作为框架模块的一部分对外公开，这通常不是我们想要做的，因为它破坏了模块化。(这就是为什么允许非模块化包含在框架模块默认为NO)

为了将Objective-C/C库公开给你的框架swift代码，我们应该为这个库定义一个单独的swift模块。然后可以使用标准的快速导入YourLegacyLibrary。

让我在一些典型场景中演示这一点:将libxml2嵌入到我们的框架中。

1. 首先需要创建一个模块。Modulemap文件，如下所示:

对于OSX框架:

module SwiftLibXML2 [system] {
  header "/usr/include/libxml2/libxml/xpath.h"
  export *
}

对于iOS框架:

module SwiftLibXML2 [system] {
  header "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/include/libxml2/libxml/xpath.h"
  export *
}

它所做的只是将头文件和它在swift模块中引用的其他头文件打包起来，这样swift就能够为这些C接口生成swift绑定。

2. 然后在你的xcode项目目录中创建一个文件夹SwiftLibXML2，并把这个模块。modulemap那里

3.在构建设置中，将$(SDKROOT)/usr/include/libxml2添加到头搜索路径中

4. 在Build Settings中，将$(SRCROOT)/SwiftLibXML2添加到Import Paths中

5. 在Project的General选项卡下，添加libxml2。tbd到链接的框架和库。

现在你可以在需要的地方导入这个模块:

import SwiftLibXML2

(如果你想看一个更完整的模块。地图的例子，我建议参考达尔文的模块。模块映射在/usr/include/module。modulemap，你需要安装Xcode命令行工具才能到达那里，参考OS X El Capitan中缺少/usr/include)

我也想补充一下我在这个问题上的经验。

总结一下:

@ambientlight的回答很棒，它解决了大部分问题。 允许非模块化报头是另一种解决方案(参见上面的一些答案)。 将框架的头标记为公共的(只有那些您想要公开的)，并将它们导入到伞形头中。

以下是我对上述答案的2个补充:

carefully check the imports in your project for headers which import your frameworks directly in them (instead of using forward declaration, if possible) -- it is not a good practice to include a header file inside another header file; sometimes this causes a problems, because if not done properly this may lead to multiple include-ing of one header and create linker issues. UPDATE: make sure that the architectures of the library and that of the target that you want to link it to match. and lastly, after doing all of the above, I still kept bumping onto that error. So I dug a little more and found (in the apple developer forums, but I lost the link :( ) that if you include the headers in the umbrella header not like this <framework/headerName.h>, but only like this "headerName.h", the problem goes away.

我尝试了最后一个，到目前为止我还没有遇到过这个问题，但是我怀疑这个解决方案只有在你应用了一些顶部的答案时才有效(注意:它们并不都相互兼容，例如，模块方法和允许非模块头包含)。

Most commonly this error is caused by the chosen answer, yet I had this error appear once by accident when dragging framework files into my new project folder. I clicked to delete the frameworks but accidentally pressed to only 'Remove Reference' to the frameworks rather than to actually delete the files completely. At this point if I opened my project folder in Finder I saw files like 'CoreLocation' and 'AudioToolbox' there. Deleting these files from the project folder and cleaning the project fixed the issue.