Portability and interoperability rules

Portability rules support portability across different platforms. Interoperability rules support interaction with COM clients.

In this section

Rule	Description
CA1401: P/Invokes should not be visible	A public or protected method in a public type has the System.Runtime.InteropServices.DllImportAttribute attribute (also implemented by the Declare keyword in Visual Basic). Such methods should not be exposed.
CA1416: Validate platform compatibility	Using platform-dependent APIs on a component makes the code no longer work across all platforms.
CA1417: Do not use OutAttribute on string parameters for P/Invokes	String parameters passed by value with the OutAttribute can destabilize the runtime if the string is an interned string.
CA1418: Use valid platform string	Platform compatibility analyzer requires a valid platform name and version.
CA1419: Provide a parameterless constructor that is as visible as the containing type for concrete types derived from 'System.Runtime.InteropServices.SafeHandle'	Providing a parameterless constructor that is as visible as the containing type for a type derived from System.Runtime.InteropServices.SafeHandle enables better performance and usage with source-generated interop solutions.
CA1420: Property, type, or attribute requires runtime marshalling	Using features that require runtime marshalling when runtime marshalling is disabled will result in run-time exceptions.
CA1421: Method uses runtime marshalling when DisableRuntimeMarshallingAttribute is applied	A method uses runtime marshalling, and runtime marshalling is explicitly disabled.
CA1422: Validate platform compatibility	Calling an API that's obsolete in a given OS (version) from a call site that's reachable from that OS (version) is not recommended.