How to use a C callback from C#?

Question

This is a .NET wrapper for the library Secret Rabbit Code (aka libsamplerate), when calling src_callback_read in CallbackRead : AccessViola

Answer 1

I have fixed it using the following :

[System::Runtime::InteropServices::UnmanagedFunctionPointerAttribute ( CallingConvention::Cdecl )]
public delegate long SRCCallback ( void *cb_data, float **data ) ;

static  IntPtr CallbackNew ( SRCCallback ^ % func, RabbitConverter converter_type, int channels, int *error, void* cb_data ) { ... }

In short : now it uses C calling convention and C# ref keyword.