# Interoperability with .NET

**URL:** https://discourse.julialang.org/t/interoperability-with-net/19611
**Category:** General Usage
**Tags:** dotnet, interoperability
**Created:** [January 14, 2019, 11:09am UTC](https://discourse.julialang.org/t/interoperability-with-net/19611 "2019-01-14T11:09:22Z")
**Posts on this page:** 1
**Showing post:** 12

<div class="post-metadata">

### Author: ![oheil](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oheil/32/220745_2.png) [@oheil](https://discourse.julialang.org/u/oheil)
#### Post date: [June 27, 2019, 7:29am UTC](https://discourse.julialang.org/t/interoperability-with-net/19611/12 "2019-06-27T07:29:26Z")

</div>

I had a hard time now struggling with running a Julia script via `include("...")` from my C# GUI.  
There wasn’t a problem when using Julia 0.6 but with 1.1 it failed silently.

Finally I found a solution and during my way to it I was able to get some exception string from the Julia call.  
This is now my current code to call Julia 1.1 (or above) and run a Julia script from C#:

```julia
using System;

using System.Runtime.InteropServices;
using System.IO;

namespace julia
{
    class NativeMethods
    {
        
        [DllImport("kernel32.dll")]
        public static extern bool SetDllDirectory(string pathName);

        [DllImport("libjulia.dll", CallingConvention = CallingConvention.Cdecl)]
        private static extern void jl_init__threading();

        [DllImport("libjulia.dll", CallingConvention = CallingConvention.Cdecl)]
        private static extern IntPtr jl_eval_string(string str);

        [DllImport("libjulia.dll", CallingConvention = CallingConvention.Cdecl)]
        private static extern IntPtr jl_exception_occurred();

        [DllImport("libjulia.dll", CallingConvention = CallingConvention.Cdecl)]
        private static extern IntPtr jl_typeof_str(IntPtr value);

        [DllImport("libjulia.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern void jl_atexit_hook(int a);

        public static void Julia(string juliaDir, string juliaScriptDir, string projectPath)
        {
            SetDllDirectory(juliaDir);

            jl_init__threading();

            string script = @"Base.include(Base,raw""d:\Temp\test.jl"";)";
            //string script = @"include(raw""d:\Temp\test.jl"";)";
            jl_eval_string(script);
            IntPtr exception = jl_exception_occurred();
            if (exception != (IntPtr)0x0)
            {
                string exceptionString = System.Runtime.InteropServices.Marshal.PtrToStringAnsi(jl_typeof_str(jl_exception_occurred()));
                Console.WriteLine(exceptionString);
            }

            jl_atexit_hook(0);
        }
    }
}

```

If you use the out-commented statement

```julia
string script = @"include(raw""d:\Temp\test.jl"";)";

```

the `exceptionString` will be `"UndefVarError"` and the script will not run.

The call is

```julia
julia.NativeMethods.Julia(juliaDir, juliaScriptDir, projectPath);

```

Parameter `juliaDir` must be the folder where libjulia.dll resides, e.g. `c:\\Programs\\Julia-1.1.0\\bin\\`.

The other two paramers (`juliaScriptDir` and `projectPath`) are not used in this example.

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