Tips for using a C library from C#

Question

I\'ve got a library in C which I\'d like to use from C#.

From what I\'ve gleaned off the internet, one idea is to wrap it in a C++ dll, and DllImport that.

Answer 1

There has been a MSDN article years ago which reulted in the InteropSignatureToolkit. This little tool is still useful to marshall C interfaces. Copy and past interface code into the "SigImp Translation Sniplet" and watch the results.

The result is the following but I have no idea how the delegate is used or if it works. So if it works add some comments.

/// Return Type: int
///param0: int
///param1: int
///param2: double*
///param3: double*
///param4: int*
public delegate int Anonymous_83fd32fd_91ee_45ce_b7e9_b7d886d2eb38(int param0, int param1, ref double param2, ref double param3, ref int param4);

public partial class NativeMethods {

    /// Return Type: int
    ///fcn: Anonymous_83fd32fd_91ee_45ce_b7e9_b7d886d2eb38
    ///m: int
    ///n: int
    ///x: double*
    ///ftol: double
    ///xtol: double
    ///gtol: double
    ///maxfev: int
    ///epsfcn: double
    ///factor: double
    [System.Runtime.InteropServices.DllImportAttribute("", EntryPoint="lmdif", CallingConvention=System.Runtime.InteropServices.CallingConvention.Cdecl)]
public static extern  int lmdif(Anonymous_83fd32fd_91ee_45ce_b7e9_b7d886d2eb38 fcn, int m, int n, ref double x, double ftol, double xtol, double gtol, int maxfev, double epsfcn, double factor) ;

}