我曾经遇到过这个问题。我意识到在移动一个类时，我已经在目标文件夹上用.h文件覆盖了.mm文件。

修复这个问题就修复了错误。

在我的例子中，我添加了一个必须使用Objective c++的框架。我找到了这个帖子:

XCode .m vs. mm

这说明了主要的。M需要重命名为main。mm，这样objective - c++类也可以被编译。

这为我解决了问题。

如果您在释放模式下构建您的Flutter项目时遇到了这个问题-这对我有帮助:

Set your build system to New Build System in File > Project Settings… delete folders ios and build_ios from your project folder. create ios module by executing flutter create . from your project folder. open Xcode and: set the IOS Deployment Target to at least 9.0 in PROJECT > Runner check your Signing & Capabilities make sure your Build Configuration is set to Release in Edit Scheme... and build for Generic iOS Device execute pod install from your project folder execute flutter pub get from your project folder

现在打开你的Xcode并构建或存档它:Product > build(或archive)

我遇到了类似的问题，我必须在每个项目配置(调试、发布和部署)和目标的构建设置中检查“仅构建活动体系结构”。

昨晚我遇到了一个类似的问题，这个问题与我在Xcode中从Finder拖拽一个类有关。

解决方案是选择Build Phases选项卡，然后选择Compile Sources，并确保将类拖到列表中。

If you're building from Unity3D 5 and also using a Prime31 plugin and you're getting this error it's probably due to a duplicate .dll. If you look through your warnings in Unity's editor one of them will tell you this and warn that it could cause build errors. To see if this is the case, type P31 in your project search field and it should pop right up, maybe even more than one. The duplicate's will have a ' 1' at the end of the file name. This is probably caused from updating the plugin in editor via the store or the Prime31 menu tab.