Category: CSharp

But I recently saw this post on stack overflow that reminded me of that game. So I thought I would share some of the code for how to do in application code compilation in .Net. Hopefully it will be of use to some people and maybe even if I get enough interest I may try and clean up the rest of the code and release it as an open source project. Because despite being painfully complicated, when it did work it was fun, at least for uber nerds like us.

RunTimeTypeCreator

 public static T CreateType(string source,   
                          IEnumerable assemblies,   
                          out List compilationErrors)   
                             where T : class  

 namespace RunTimeTypeCreator.Tests   
 {   
    public interface ITestType   
    {   
      bool Success { get; }   
    }   
    public class RunTimeTypeCreatorTests   
    {   
       public static bool TestVariable = false;   
       public void Example()   
       {   
          const string source = @"   
 using RunTimeTypeCreator.Tests;   
 public class TestTypeClass : RunTimeTypeCreatorTests.ITestType   
 {   
    public bool Success { get { return RunTimeTypeCreatorTests.TestVariable; } }   
 }";   
          List compilationErrors;       
          var type = RunTimeTypeCreator.CreateType(source,   
                     new[] { "RunTimeTypeCreator.Tests.dll" }, //the name of this assembly  
                     out compilationErrors);   
          TestVariable = false;   
          //will print true   
          Console.WriteLine(type.Success)   
          //will print false   
          TestVariable = true;   
          Console.WriteLine(type.Success)   
       }   
    }   
 }   

 var csc = new CSharpCodeProvider();   
   
 var parameters = new CompilerParameters   
     {   
      //we don't want a physical executable in this case   
      GenerateExecutable = false,   
      //this is what allows it to access variables in our domain   
      GenerateInMemory = true   
     };   
   
 //add all the assmeblies we care about   
 foreach (var assembly in assemblies)   
     parameters.ReferencedAssemblies.Add(assembly);   
   
 //compile away, will load the class into memory   
 var result = csc.CompileAssemblyFromSource(parameters, source);   
   
 //we compiled succesfully so now just use reflection to get the type we want   
     var types = result.CompiledAssembly.GetTypes()   
              .Where(x => typeof(T).IsAssignableFrom(x)).ToList();    
   
 //create the type and return   
 return (T)Activator.CreateInstance(types.First());