WinRT: C++ C# interop grief

[Super Lloyd]

I created a simple WinRT C++ class to help having meaningful exception, it looks like that

public enum class ErrorCodes
{
	CodeStart = 0x0200, CodeEnd = CodeStart + 100, NotErrorCode = CodeEnd - 1,
	StupideError1 = CodeStart + 1,
	StupideError2 = CodeStart + 2,
};

public ref class Class1 sealed
{
private:
	Class1() {}

public:
	static void Throw(ErrorCodes c);
	static ErrorCodes GetCode(Platform::Exception^ ex);
};

However, when I try to use it in C#, with code like that

		try
		{
			Class1.Throw(ErrorCodes.StupideError1);
		}
		catch (Exception ex)
		{
			var c = Class1.GetCode(ex);
		}

I got the following compiler error in my C# project: 2>C:\Dev\W8\App1\App1\App.xaml.cs(42,5,42,8): error CS0012: The type 'Platform.Exception' is defined in an assembly that is not referenced. You must add a reference to assembly 'platform, Version=255.255.255.255, Culture=neutral, PublicKeyToken=null, ContentType=WindowsRuntime'. 2>C:\Dev\W8\App1\App1\App.xaml.cs(42,13,42,31): error CS1502: The best overloaded method match for 'CppComp.Class1.GetCode(Platform.Exception)' has some invalid arguments 2>C:\Dev\W8\App1\App1\App.xaml.cs(42,28,42,30): error CS1503: Argument 1: cannot convert from 'System.Exception' to 'Platform.Exception' How could I fix that?

A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station.... _________________________________________________________ My programs never have bugs, they just develop random features.

[Super Lloyd]

Worked around code by not exposing method using Platform::Exception(), just so:

public enum class ErrorCodes
{
	CodeStart = 0x0200, CodeEnd = CodeStart + 100, NotErrorCode = CodeEnd - 1,

	NullContext = CodeStart + 1,
	ContextNotReady = CodeStart + 2,
};

public ref class ExHelper sealed
{
public:
	static void Throw(ErrorCodes c);
	static ErrorCodes GetCode(int hr);

internal:
	static Platform::Exception^ CreateException(ErrorCodes c);
	static ErrorCodes GetCode(Platform::Exception^ ex);

private:
	ExHelper() {}
};

Remark Once I referenced platform.winmd in my C# project (from: C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcpackages) I got too many compilation errors suddenly appearing!! :wtf:

A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station.... _________________________________________________________ My programs never have bugs, they just develop random features.

[FrankLavigne]

Interop between languages (aka WinMD libraries/WinRT components) have to use native Windows Runtime types on publicly exposed members and methods.