CODEWITHSUNDEEP
c#.netcinteropclr
Steve
Steve

Reputation:

How to export a struct definition from a native C .dll for use in C#

I know how to extern methods in the .dll, how do I extern structs?

I want to create a C method such as

extern __declspec(dllexport) myStructure getStruct();

where myStructure is something like

typedef struct
{
   int A;
   int B;
   char C;
} myStructure;

How can I call getStruct() from a piece of C# code without first defining the same exact struct in C#? I want to keep a centralized declaration of myStructure so that I only have to make code changes in one place.

Thanks a bunch!

Upvotes: 5

Views: 2392

Answers (2)

Chris Thompson
Chris Thompson

Reputation: 16841

I've done a bit of P/Invoke with C# and I've always had to define structs in C# that correspond to the Win32 struct by definition. The runtime uses the struct definition to marshal the data from unmanaged to managed. Preet's answer is probably the best.

Upvotes: 1

Preet Sangha
Preet Sangha

Reputation: 65496

What about doing it another way? Define the struct in C# in T4 and then cross gen to the new format in each of the projects:

ie. base.tt

// C# definition of struct

in gencsharp.tt in the C# project include "base.tt" ... output the C#

in gencplusplus.tt in the CPP project include "base.tt" ... use C# to gen a cpp .h file

Upvotes: 3

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