C28221

Note

This article applies to Visual Studio 2015. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

warning C28221: String expression expected for the parameter in the annotation

This warning indicates that a parameter to an annotation is expected to be a string, and some other type was encountered. This usually indicates an incorrectly coded annotation macro and is not expected to be seen in normal use.