Passing strings between C# and Fortran, sample

Zhong_Shengjun

FStringTest.rar (14.84 KB, 下载次数: 34481)

2011-10-19 00:17 上传

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• Fortran passes the length of strings as hidden arguments. Using "String" type in C# to pass strings to Fortran, and add string lengths as addtional arguments after the actual arguments.
• Using StringBuilder to pass Fortran strings to C#. The Fortran strings shall be null terminated, and the StringBuilder in C# shall has enough capacity.
• In C# prototype declaration, the DllImport property "CharSet" shall be set to "CharSet=CharSet.Ansi".

1. The Fortran code:

! This sample demonstarte passing strings from other languages to Fortran
Subroutine WriteStrings(str1,str2)
  !DEC$ ATTRIBUTES DLLEXPORT, StdCall, Reference, Alias:'WriteStrings'::WriteStrings
  Character*(*) str1,str2
  Write(*,*) 'Printed by Fortran subrotine ...'
  Write(*,*) str1
  Write(*,*) str2
End subroutine

! This sample demonstarte passing strings to other languages from Fortran
Subroutine GetStrings(str1,str2)
  !DEC$ ATTRIBUTES DLLEXPORT, StdCall, Reference, Alias:'GetStrings'::GetStrings
  Character*(*), intent(out) :: str1
  Character*(*), intent(out) :: str2
  ! String chall be null terminated
  str1='The first string from Fortran subroutine'C
  str2='The second string from Fortran subroutine'C
End subroutine

2. The C# interface class:

    public class ForLib
    {
        [DllImport("FStringDLL.dll",CallingConvention=CallingConvention.StdCall,CharSet= CharSet.Ansi)]
        public static extern void WriteStrings(String str1,String str2, int LenStr1, int LenStr2);
        [DllImport("FStringDLL.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi)]
        public static extern void GetStrings(StringBuilder sb1, StringBuilder sb2, int Len1,int Len2);
    }

3. The C# test code:

        static void Main(string[] args)
        {
            String str1="C# string: Hello, world!";
            String str2 = "C# string: Another string";
            ForLib.WriteStrings(str1, str2, str1.Length, str2.Length);
            // The capacity of strings should be enough
            int Len1 = 1024, Len2 = 1024;
            StringBuilder sb1 = new StringBuilder(Len1);
            StringBuilder sb2 = new StringBuilder(Len2);
            ForLib.GetStrings(sb1, sb2, Len1, Len2);
            Console.WriteLine("Printed by C# ...");
            Console.WriteLine(sb1.ToString());
            Console.WriteLine(sb2.ToString());
            Console.ReadKey();
        }