Question

Here’s my code:

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


namespace ConsoleApplication1
{
    class Program
    {
        public int xx = 1; // variable I want to access from the runtime code

        static void Main(string[] args)
        {            
            CSharpCodeProvider provider = new CSharpCodeProvider();
            CompilerParameters parameters = new CompilerParameters();
            parameters.GenerateInMemory = true;
            parameters.ReferencedAssemblies.Add("System.dll");


            CompilerResults results = provider.CompileAssemblyFromSource(parameters, GetCode());
            var cls = results.CompiledAssembly.GetType("ConsoleApplication1.Program");
            var method = cls.GetMethod("DynamicMethod", BindingFlags.Static | BindingFlags.Public);
            method.Invoke(null, null);

            int a = int.Parse(Console.ReadLine()); // pause console
        }       


        static string[] GetCode()
        {
            return new string[]
            {
            @"using System;

            namespace ConsoleApplication1
            {
                class Program
                {
                    public static void DynamicMethod()
                    {                        
                        Console.WriteLine(""Hello, world!"");
                    }
                }
            }"
            };
        }
    }
}

I would like to know if It’s possible to access variable int xx from the runetime code (eg. putting xx = 2; line after “hello world”. That would be awesome
Thanks 🙂

Answer 1

Yes, you can make that available, but you need to:

• add a reference to the assembly that contains xx (I’m calling this assembly StaticAssembly, for convenience – so it is probably StaticAssembly.exe, the console exe that is running)
• make Program in StaticAssembly a public type so that it is accessible
• either make xx into a static field, or instantiate an instance of Program and pass it to the dynamic code somehow

The following works, for example (I’m using the “instantiate an instance and pass it” approach, so I’ve added a parameter to DynamicMethod):

using System;
using System.CodeDom.Compiler;
using System.Reflection;
using Microsoft.CSharp;


namespace StaticAssembly
{
    public class Program
    {
        public int xx = 1; // variable I want to access from the runtime code

        static void Main(string[] args)
        {
            CSharpCodeProvider provider = new CSharpCodeProvider();
            CompilerParameters parameters = new CompilerParameters();
            parameters.GenerateInMemory = true;
            parameters.ReferencedAssemblies.Add("System.dll");
            parameters.ReferencedAssemblies.Add("StaticAssembly.exe");

            CompilerResults results = provider.CompileAssemblyFromSource(parameters, GetCode());
            var cls = results.CompiledAssembly.GetType("GeneratedAssembly.Program");
            var method = cls.GetMethod("DynamicMethod", BindingFlags.Static | BindingFlags.Public);
            var p = new Program();
            p.xx = 42;
            method.Invoke(null, new object[] {p});

            int a = int.Parse(Console.ReadLine()); // pause console
        }


        static string[] GetCode()
        {
            return new string[]
            {
            @"using System;

            namespace GeneratedAssembly
            {
                class Program
                {
                    public static void DynamicMethod(StaticAssembly.Program p)
                    {                        
                        Console.WriteLine(p.xx);
                        Console.WriteLine(""Hello, world!"");
                    }
                }
            }"
            };
        }
    }
}