C#反射机制问题
dll文件Code如下(保存文件名为ReflectTest.dll)
using System;
using System.Collections.Generic;
using System.Text;

namespace Webtest
{
  public class ReflectTest
  {
   
  public ReflectTest()
  {
  
  }
  public string WriteString(string s)
  {
  return "欢迎您，" + s;
  }

  public static string WriteName(string s)
  {
  return "欢迎您光临，Crazycoder.cn" + s;
  }


  public string WriteNoPara()
  {
  return "您使用的是无参数方法";
  }
 }
}

页面代码如下:
 protected void Page_Load(object sender, EventArgs e)
  {
  System.Reflection.Assembly ass;
  Type type ;
  object obj;
  try
  {
  ass = System.Reflection.Assembly.LoadFile(@"f:\Test.dll");
  type = ass.GetType("Webtest.ReflectTest");-----------------------------------------1
  System.Reflection.MethodInfo method = type.GetMethod("WriteString");
  obj = ass.CreateInstance("Webtest.ReflectTest");
  string s = (string)method.Invoke(obj,new string[]{"jianglijun"});
  Response.Write(s+"<br>");
  method = type.GetMethod("WriteName");
  s = (string)method.Invoke(null,new string[]{"jianglijun"});
  Response.Write(s+"<br>");
  method = type.GetMethod("WriteNoPara");
  s = (string)method.Invoke(obj,null);
  Response.Write(s+"<br>");
  method = null;
  }
  catch(Exception ex)
  {
  Response.Write(ex+"<br>");
  }
  finally
  {
  ass = null;
  type = null;
  obj = null;
  }
}
我在运行跟踪时发现,在1位置时type的值为Null.请问这是什么问题引起的?如何解决?
C#使用反射机制时要哪些条件?请前辈们多多提点~~~

------解决方案--------------------
你看下数组的长度~~这里有个叫程序集的名称~~ 应该和你的 Webtest.ReflectTest有区别