Call fortran dll from C#

[libishkb]

I am trying to call a fortran dll from c# code. But i get the following error message.An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B). Could any one please tell me where I am going wrong? The codes are given below.

Fortran code

!  lwing.f90 
!
!  FUNCTIONS/SUBROUTINES exported from lwing.dll:
!  lwing - subroutine 
!
! Expose subroutine lwing to users of this DLL
  !
  !DEC$ ATTRIBUTES DLLEXPORT::lwing
 
  ! Variables
SUBROUTINE lwing(span,dfuse,lenw)
!-------------------------------------------------------------------
! This subroutine calculates the wing length in cantilever position
 
!Input arguments: span- wing span
!                 dfuse- Fuselage diameter
!Output Arguments: lenw- Length of wing in cantilever position
!-------------------------------------------------------------------
IMPLICIT NONE
REAL, INTENT(IN)::dfuse,span
REAL, INTENT(OUT)::lenw
 
 
lenw=(span-dfuse)/2;
 
END SUBROUTINE lwing

C# Code

namespace ggg
{
    public class Model
    {
        [DllImport("lwing.dll", CharSet = CharSet.Ansi, CallingConvention = CallingConvention.Winapi)] /* Import from DLL, the C# compiler provides a rudimentry check of the signature */
        public static extern void lwing(ref double span,ref double dfuse,ref double lenw);
        static void Main()
        {
            double a = 1;
            double b = 1;
            double c = 1;
            lwing(ref a,ref b,ref c);
        }
    }
}

[Plater]

Try getting rid of this section:
CallingConvention = CallingConvention.Winapi

[libishkb]

I changed the 'Platform Target' from the properties of my C# project from 'AnyCPU' to 'x86'.

[Plater]

Did that turn out to be the solution?

[libishkb]

yes strangely it was....