Generating DLL assembly dynamically at run time

Question

Currently I have some code that is being generated dynamically. In other words, a C# .cs file is created dynamically by the program, and the intention is to include this C# file in another project.

The challenge is that I would like to generate a .DLL file instead of generating a C# .cs file so that it could be referenced by any kind of .NET application (not only C#) and therefore be more useful.

Answer 1

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

CSharpCodeProvider codeProvider = new CSharpCodeProvider();
ICodeCompiler icc = codeProvider.CreateCompiler();
System.CodeDom.Compiler.CompilerParameters parameters = new CompilerParameters();
parameters.GenerateExecutable = false;
parameters.OutputAssembly = "AutoGen.dll";
CompilerResults results = icc.CompileAssemblyFromSource(parameters, yourCodeAsString);

Adapted from http://support.microsoft.com/kb/304655

Answer 2

The non-deprecated way of doing it (using .NET 4.0 as previous posters mentioned):

using System.CodeDom.Compiler;
using System.Reflection;
using System;
public class J
{
    public static void Main()
    {       
        System.CodeDom.Compiler.CompilerParameters parameters = new CompilerParameters();
        parameters.GenerateExecutable = false;
        parameters.OutputAssembly = "AutoGen.dll";

        CompilerResults r = CodeDomProvider.CreateProvider("CSharp").CompileAssemblyFromSource(parameters, "public class B {public static int k=7;}");

        //verify generation
        Console.WriteLine(Assembly.LoadFrom("AutoGen.dll").GetType("B").GetField("k").GetValue(null));
    }
}

Answer 3

Right now, your best bet is CSharpCodeProvider; the plans for 4.0 include "compiler as a service", which will make this fully managed.