C#反射实例化类并调用带参数的方法

string method = Request["METHAD"];
            string ClassNamespace = method.Substring(0, method.LastIndexOf("."));// "Bss.Web.Login";   
            object objType = CreateObject(Request["DLL"], ClassNamespace);
            //Assembly assembly = Assembly.Load("Mobizone.BLL");
            //Type type = assembly.GetType("Mobizone.BLL." + dataSource.Split('.')[0]);
            //object obj = Activator.CreateInstance(type); 实例化反射类


            Type ht = objType.GetType();
            MethodInfo methodInfo = ht.GetMethod(method.Substring(method.LastIndexOf(".") + 1));
            int length = Request.Form.AllKeys.Length;
            ParameterInfo[] paramsInfo = methodInfo.GetParameters();//得到指定方法的参数列表   


            object[] obj = new object[length];
            for (int i = 0; i < length; i++)
            {
                Type tType = paramsInfo[i].ParameterType;
                //如果它是值类型,或者String   
                if (tType.Equals(typeof(string)) || (!tType.IsInterface && !tType.IsClass))
                {
                    //改变参数类型   
                    obj[i] = Convert.ChangeType(Request.Form[i], tType);
                }
                else if (tType.IsClass)//如果是类,将它的json字符串转换成对象   
                {
                    obj[i] = Newtonsoft.Json.JsonConvert.DeserializeObject(Request.Form[i], tType);
                }
            }
            //执行方法   
            object returnValue = methodInfo.Invoke(objType, obj);