键入编组调用从C＃，Fortran子例程 [英] Type marshalling to call a fortran subroutine from C#

问题描述

我试图使用P / Invoke调用从C＃代码FORTRAN77子程序 - 如果你有兴趣，我试图总结一些（由ARPACK库提供的功能的 http://www.caam.rice.edu/software/ARPACK ）。我有2个问题。

I'm trying to call a FORTRAN77 subroutine from C# code using P/invoke - in case you're interested, I'm trying to wrap some of the functionality offered by the ARPACK library (http://www.caam.rice.edu/software/ARPACK). I have 2 questions.

首先，我找不到任何地方就在这种背景下型编组站明确的指示。更具体地讲，这里是在我的FORTRAN子程序声明的类型：

First off, I couldn't find clear instructions anywhere regarding type marshalling in this context. More specifically, here are the types that are declared in my FORTRAN subroutine:

       subroutine getEigenVectors
      &   ( Matrix, n, which, nev, ncv, maxn, maxnev, maxncv, ldv, v, d)

 c     %------------------%
 c     | Scalar Arguments |
 c     %------------------%

       character        which*2
       integer          n, nev, maxn, maxnev, maxncv, ldv

 c     %-----------------%
 c     | Array Arguments |
 c     %-----------------%
 c
       Real           
      &                 Matrix(n,n), v(ldv,maxncv), d(maxncv,2)

我发现了一些有价值的信息在这里：
我应该的MarshalAs ？在Fortran语言字符类型，从中我暗示（我可能是错的），我应该使用：

I found some valuable info here: What Should I MarshalAs for Character Type in Fortran?, from which I implied (I might be wrong) that I should use:

• [的MarshalAs（UnmanagedType.I4）INT 在整数传递


• [的MarshalAs（UnmanagedType.LPArray）字节[] 来的字符串传递

• [MarshalAs(UnmanagedType.I4)] int to pass in integers
• [MarshalAs(UnmanagedType.LPArray)] byte[] to pass in character strings

不过，我完全不知道是做什么用的真实阵列。 有没有人有任何想法？

However, I have absolutely no idea what to do with the Real arrays. Does anyone have any idea on that?

其次，我很困惑，我是否应该通过我的论点作为参考与否。我绝不熟悉FORTRAN - 我知道，这使得任务有点困难;然而，只有ARPACK做我想做，我没地方读尽管这FORTRAN子程序采取一切它们的参数作为默认的引用内容。 我应该因此通过所有参数作为参考？

Secondly, I am confused as to whether I should pass my arguments as reference or not. I am by no means familiar with FORTRAN - I know, that makes the task a little difficult; however, only ARPACK does what I would like to do.I did read somewhere though that FORTRAN subroutines take all their arguments as reference by default. Should I therefore pass all arguments as references?

在此先感谢您的帮助！
纪尧姆

Thanks in advance for your help! Guillaume

修改（11年8月6日）

因此，这里是我的最终看法：

So here's my final take:

    [DllImport("Arpack.dll", EntryPoint = "#140")]
    private static extern void getEigenVectors(
        [MarshalAs(UnmanagedType.LPArray)] ref float[,] matrix, 
        [MarshalAs(UnmanagedType.I4)] ref int n,
        [MarshalAs(UnmanagedType.LPArray)] ref byte[] which,
        [MarshalAs(UnmanagedType.I4)] int whichLength,
        [MarshalAs(UnmanagedType.I4)] ref int nev, 
        [MarshalAs(UnmanagedType.I4)] ref int ncv,
        [MarshalAs(UnmanagedType.I4)] ref int maxn,
        [MarshalAs(UnmanagedType.I4)] ref int maxnev,
        [MarshalAs(UnmanagedType.I4)] ref int maxncv,
        [MarshalAs(UnmanagedType.I4)] ref int ldv,
        [MarshalAs(UnmanagedType.LPArray)] ref float[,] v,
        [MarshalAs(UnmanagedType.LPArray)] ref float[,] d
    );

有几件事情我在这里所做的：

Several things I did here:

作为编组 UnmanagedType.I4 来匹配FORTRAN

• 通 INT 对象整数对象


• 通浮法[，] 尺寸（M，N）和编组为对象 UnmanagedType.LPArray 来匹配FORTRAN 雷亚尔（N，M）对象



• 通字节[] 对象中获取编组为 UnmanagedType.LPArray 来匹配FORTRAN 字符* ñ的对象。在字节[] 对象的计算方法如下：

• Pass int objects marshalled as UnmanagedType.I4 to match FORTRAN integer objects
• Pass float[,] objects of size (m, n) and marshalled as UnmanagedType.LPArray to match FORTRAN Real(n,m) objects

• Pass byte[] objects obtained marshalled as UnmanagedType.LPArray to match FORTRAN Character*n objects. The byte[] objects are computed as follows:

System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
byte[] which = encoding.GetBytes(myString);

传递 INT 对象按价值计算，整理为 UnmanagedType.I4 来表示字符串的长度。请注意，我试图把该参数字符串之后以及在参数列表的末尾。

Pass an int object BY VALUE and marshalled as UnmanagedType.I4 to indicate the length of the string. Note that I tried to put that argument right after the string as well as at the end of the arguments list.

这是我最好的射击 - 非此非彼的所有其他的事情我试着努力。该方法将执行，但它退出超快速（当它应该做一些相当严重的计算）。此外，我的3个阵列被转化成怪异单维数组。在这里，有什么调试器给我：

This is my best shot - neither this nor all the other things I tried worked. The method will execute, however it exits super fast (when it's supposed to be doing some pretty severe computations). Moreover, my 3 arrays are transformed into weird uni-dimensional arrays. Here what the debugger gives me:

任何想法？

推荐答案

我建议你先一些小的测试代码。一些子程序用简单的参数编译FORTRAN .dll和玩弄的 C＃的获取调用工作。你也不妨与许多论据来包装的Fortran成一个单一的结构（键入关键字），这使得互操作容易得多。

I suggest you start with some small test code. Compile a FORTRAN .dll with some subroutines with simple parameters and play around with C# to get the calling to work. Also you may wish to wrap the Fortran with many arguments into a single structure (TYPE keyword), which makes the interop so much easier.

下面是一个工作的例子，你可以用得到它是如何工作的很多想法

Here is a working example that you can use the get many ideas of how it works.

原始FORTRAN代码：

Original FORTRAN code:

  SUBROUTINE CALC2(BLKL,BLKW, N_LAMINA,N_SLICE, LOAD, SLOP,SKW,    &
                    DIA1,DIA2, Y1, Y2, N1, N2, DROP1, DROP2,        &
                    PARRAY, P_MAX, P_MAX_INDEX, ENDEFCT)
  !DEC$ ATTRIBUTES DLLEXPORT :: CALC2
  !DEC$ ATTRIBUTES ALIAS:'CALC2' :: CALC2
  !DEC$ ATTRIBUTES VALUE :: BLKL, BLKW, N_LAMINA, N_SLICE, LOAD, SLOP, SKW
  !DEC$ ATTRIBUTES VALUE :: DIA1, DIA2, Y1, Y2, N1, N2
  IMPLICIT NONE
  INTEGER*4, INTENT(IN) ::N_LAMINA, N_SLICE
  REAL*4, INTENT(IN) :: BLKL, BLKW, LOAD, SLOP, SKW,     &
                        DIA1, DIA2, Y1, Y2, N1, N2,   &
                        DROP1(MAX_LAMINA), DROP2(MAX_LAMINA)
  REAL*4, INTENT(OUT):: PARRAY(MAX_PATCH), P_MAX
  INTEGER*4, INTENT(OUT) :: P_MAX_INDEX, ENDEFCT
  INTEGER*4 :: NDIAG, N_PATCH
  REAL*4 :: SLNG, SWID
  REAL*4 :: DROPS_1(MAX_LAMINA), DROPS_2(MAX_LAMINA)

...

  END SUBROUTINE CALC2

在不同的标量和数组值真正的和以整数形式。例如 DROP1 输入一维数组。 粒子阵列是一个允许输出二维数组作为一维数组。 BLKL左张力传感器输入浮动。

with various scalar and array values in real and integer form. For example DROP1 is input 1D array. PARRAY is outputing a 2D array as a 1D array. BLKL are input floats.

注意！DEC $属性value 装修要避免宣告一切， REF 。

Notice the !DEC$ ATTRIBUTES VALUE decoration to avoid declaring everything as ref.

在 C＃的代码由

    [DllImport("mathlib.dll")]
    static extern void CALC2(float major_dim, float minor_dim, 
        int N_lamina, int N_slices, float total_load, 
        float slope, float skew, float diameter_1, float diameter_2, 
        float youngs_1, float youngs_2, float nu_1, float nu_2, 
        float[] drops_1, float[] drops_2, float[] pressures, 
        ref float p_max, ref int p_max_index, ref EndEffect end_effect);

...
   {
        float max_pressure = 0;
        int max_pressure_index = 0;
        float[] pressures = new float[Definition.MAX_PATCH];
        EndEffect end_effect = EndEffect.NO;

        CALC2(length, width, lamina_count, slice_count, load, slope, skew, 
            dia_1, dia_2, y_1, y_2, n_1, n_2, drops_1, drops_2, pressures, 
            ref max_pressure, ref max_pressure_index, ref end_effect);
    }

的注意的我不传递任何字符串。

note I do not pass any strings.

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