In given below code ExecuteCode() is a method  which is use for  run time compilation. codeToCompile is a  complete method which you have to execute and userid and password are the passing parameters of method body codeToCompile .

using System.CodeDom.Compiler;
using System.Reflection;

namespace CodeExecution
{
    public class CodeExecution
    {
        public static string ExecuteCode(string codeToCompile, string userid, string password)
        {
            CSharpCodeProvider cSharpCodeProvider = new CSharpCodeProvider();
            ICodeCompiler iCodeCompiler = cSharpCodeProvider.CreateCompiler();
            CompilerParameters compilerParameters = new CompilerParameters();

            compilerParameters.ReferencedAssemblies.Add("system.dll");

            compilerParameters.CompilerOptions = "/t:library";
            compilerParameters.GenerateInMemory = true;
            StringBuilder sb = new StringBuilder("");

            sb.Append("using System;\n");
            sb.Append("namespace CodeExecution{ \n");
            sb.Append("public class CodeExecution{ \n");
            sb.Append(codeToCompile + "\n");
            sb.Append("} \n");
            sb.Append("}\n");

            CompilerResults compilerResults = iCodeCompiler.CompileAssemblyFromSource(compilerParameters, sb.ToString());
            if (compilerResults.Errors.Count > 0)
            {
                return null;
            }

            System.Reflection.Assembly a = compilerResults.CompiledAssembly;
            object o = a.CreateInstance("CodeExecution.CodeExecution");  //get namespace name and then class name- you can change according to your code
            Type t = o.GetType();
            MethodInfo mi = t.GetMethod("StringParser"); //StringParser is the name of method-you can change according to your code

            object[] oParams = new object[] { userid, password };  //parameters of method
            object s = mi.Invoke(o, oParams);
            string result = (string)s;
            return result;
        }
    }

}

Referred Link : http://www.codeproject.com/Articles/11939/Evaluate-C-Code-Eval-Function

Hope this code will help you.Thanks