求解，关于C#引用类的

代码：
文件1：    class Class2
    {
        public Class2()
        {
            Console.WriteLine("class2");
        }
    }
文件2：//用的是动态编译,代码可以不看,只看 红色字体的部分
       static void Main(string[] args)
        {            CSharpCodeProvider codeProvide = new CSharpCodeProvider();
            ICodeCompiler codeCompiler = codeProvide.CreateCompiler();
            CompilerParameters compilerParameters = new CompilerParameters();
            compilerParameters.ReferencedAssemblies.Add("System.dll");
            compilerParameters.ReferencedAssemblies.Add("System.Core.dll");
            compilerParameters.GenerateExecutable = false;
            compilerParameters.GenerateInMemory = true;
            CompilerResults cr = codeCompiler.CompileAssemblyFromSource(compilerParameters, GenerateCode());
            if (cr.Errors.HasErrors)
            {
                Console.WriteLine("编译错误：");
                foreach (CompilerError err in cr.Errors)
                {
                    Console.WriteLine(err.ErrorText);
                }
            }
            else
            {
                Assembly assembly = cr.CompiledAssembly;
                object helloword = assembly.CreateInstance("PINQ_test_ConsoleApplication.HelloWorld");
                MethodInfo methodInfo = helloword.GetType().GetMethod("OutPut");
                object[] objs = new object[1];
                objs[0] = "fuckYou";
                char[] cc = (char[])methodInfo.Invoke(helloword, objs);
                Console.WriteLine(cc[0].ToString());
                Console.WriteLine(new String(cc));
            }            Console.ReadLine();
        }  
             static string GenerateCode()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("using System;using System.Linq;");
            sb.Append(Environment.NewLine);
            sb.Append("namespace PINQ_test_ConsoleApplication");
            sb.Append(Environment.NewLine);
            sb.Append("{");
            sb.Append(Environment.NewLine);
            sb.Append("      public class HelloWorld");
            sb.Append(Environment.NewLine);
            sb.Append("      {");
            sb.Append(Environment.NewLine);
            sb.Append("          public char[] OutPut(string str)");
            sb.Append(Environment.NewLine);
            sb.Append("          {");
            sb.Append(Environment.NewLine);
            sb.Append("Class2 cc=new Class2();               return str.ToArray();");
            sb.Append(Environment.NewLine);
            sb.Append("          }");
            sb.Append(Environment.NewLine);
            sb.Append("      }");
            sb.Append(Environment.NewLine);
            sb.Append("}");            string code = sb.ToString();
            //Console.WriteLine(code);
            //Console.WriteLine();            return code;
        }这个时候显示的是错误的,因为这是两个文件,虽然我定义了同一个命名空间,但是,系统好像并不把他们当做一个命名空间处理,请问,应该如何解决?