C# Compiling User Supplied Code And Using

Question

What I'm trying to do is allow a user to write a method in a textbox and have my code call that method. This will eventually be used in a demo applet for optimization given a goal function.

So I've been working with a sample console application but I'm having trouble. I've checked stack overflow and codeproject and other sources, and have got to the point where I can compile the code. But I'm lost at how to call it and only access a method.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;

namespace CodeCompilerTest
{
    class Program
    {
        static void Main(string[] args)
        {
            CodeDomProvider codeProvider = CodeDomProvider.CreateProvider("CSharp");

            CompilerParameters parameters = new CompilerParameters();
            //parameters.GenerateExecutable = false;
            parameters.GenerateInMemory = true;
            //parameters.OutputAssembly = "Output.dll";

            string SourceString = @"
                                   using System;
                                   using System.Collections.Generic;
                                   using System.Text;

                                   namespace testone 
                                   {
                                        public class myclass
                                        {
                                            public double Main()
                                            {
                                                return testd(5,8);
                                            }

                                            public double testd(double a, double b)
                                            { 
                                                return a+b;
                                            } 
                                        } 
                                    }";

            CompilerResults results = codeProvider.CompileAssemblyFromSource(parameters, SourceString);

            if (results.Errors.Count > 0)
            {
                foreach (CompilerError CompErr in results.Errors)
                {
                    Console.WriteLine("Line number " + CompErr.Line + ", Error Number: " + CompErr.ErrorNumber + ", '" + CompErr.ErrorText + ";");
                }
                Console.ReadLine();
            }

            Assembly mAssembly = results.CompiledAssembly;
            Type scripttype = mAssembly.GetType("myclass");
            Object rslt = new Object();
            Object[] argin = {5, 8};
            //rslt  = scripttype.GetMethod("Main").Invoke(null, null);
            rslt = scripttype.InvokeMember("Main", BindingFlags.InvokeMethod | BindingFlags.Public |BindingFlags.Static, null, null, null);
            Console.WriteLine(((double)rslt).ToString());
            Console.ReadLine();
        }
    }
}

I've tried different combinations on how to call the Invoke on the method and keep getting errors. What I want to be able to do is have the user define a function like this:

public double funcname(double x, double y)
{
    return x+y;
}

And then I could just call funcname directly. If this is not doable, I'll take what I can get at this point.

Any help or guidance would be appreciated. Thanks.

Sameh · Answer 1 · 2012-10-29T14:57:17.103

I believe this article will help you to access the method directly through using interfaces http://www.codeproject.com/Articles/26312/Dynamic-Code-Integration-with-CodeDom

Maybe the below is not relevant directly to your request, but I believe that you need to use Activator to create an instance of the class so you can call the testd method I mean your code defined has no object, just class definition.
Also I used GetTypes()[0] because GetType() didn't work for me

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;

namespace CodeCompilerTest
{
    class Program
    {
        static void Main(string[] args)
        {
            CodeDomProvider codeProvider = CodeDomProvider.CreateProvider("CSharp");

            CompilerParameters parameters = new CompilerParameters();
            //parameters.GenerateExecutable = false;
            parameters.GenerateInMemory = true;
            //parameters.OutputAssembly = "Output.dll";

            string SourceString = @"
                                   using System;
                                   using System.Collections.Generic;
                                   using System.Text;

                                   namespace testone 
                                   {
                                        public class myclass
                                        {
                                            public double testd(double a, double b)
                                            { 
                                                return a+b;
                                            } 
                                        } 
                                    }";

            CompilerResults results = codeProvider.CompileAssemblyFromSource(parameters, SourceString);

            if (results.Errors.Count > 0)
            {
                foreach (CompilerError CompErr in results.Errors)
                {
                    Console.WriteLine("Line number " + CompErr.Line + ", Error Number: " + CompErr.ErrorNumber + ", '" + CompErr.ErrorText + ";");
                }
                Console.ReadLine();
            }

            Assembly mAssembly = results.CompiledAssembly;
            Type scripttype = mAssembly.GetTypes()[0];
            Object myObject = Activator.CreateInstance(scripttype);
            double  rsltd = 0.0;
            Object[] argin = { 5.0, 8.0 };
            rsltd  =(double) scripttype.GetMethod("testd").Invoke(myObject,argin);
          //  object rslt = new object();
           // rslt = scripttype.InvokeMember("testd", BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Static, null, null, null);
       Console.WriteLine(rsltd.ToString());
       Console.ReadLine();
        }
    }
}

score 1 · Accepted Answer · answered May 12 '11 at 16:16

1

You need to include the namespace in the GetType call.
(Or remove the namespace from the source)

You may prefer to call GetTypes() and see all of the types defined in the assembly instead.

answered May 12 '11 at 16:16

SLaks

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So that allows me to call the function using the Invoke method. Do you know of a way to just call it like "testd(5,8)"? The eventual hope is to the user supplied function as a delegate to dll. – Tim Felty May 12 '11 at 16:22
Another useful resource that more or less says the same thing: http://stackoverflow.com/questions/1698870/accessing-class-and-function-after-compiling-compiledassembly – Tim Felty May 12 '11 at 16:23
@Tim: Call `GetTypes()` and find a type that has the function you're looking for. – SLaks May 12 '11 at 16:25
Seems there was some confusion. I can call testd() using the invoke method. But I was wondering if there was a way to have it accessible in the main where i can just say double x = testd(a,b). – Tim Felty May 12 '11 at 17:10
@Tim: No; the compiler cannot know what `testd` is. Even `dynamic` isn't quite enough for that. – SLaks May 12 '11 at 17:13
Alright, thanks. I thought it would not be able to, but I'm happy with what I have. – Tim Felty May 12 '11 at 18:02

C# Compiling User Supplied Code And Using

2 Answers2