C#使用域进行加载dll获取方法名称被占用

public class MyMarshalByRefObject : MarshalByRefObject
{
public string dll_path = string.Empty;
Assembly assembly = null;

public void Load_Dll()
{
assembly = Assembly.LoadFile(dll_path);
}
/// <summary>
/// 运行规则
/// </summary>
/// <param name="strtype">空间</param>
/// <param name="MethodName">函数名</param>
/// <param name="parameters">参数</param>
/// <param name="types">参数对应类型</param>
public void RunCommand(string strtype, string MethodName, object[] parameters = null, Type[] types = null )
{
if (MethodName != "")
{
//创建类实例
object tdll = assembly.CreateInstance(strtype);
if (types == null)
{
types = new Type[] { };
}
//获取方法
MethodInfo m = tdll.GetType().GetMethod(MethodName, types);
//委托调用
object obj = m.Invoke(tdll, parameters);
string message = "函数名：" + MethodName + "\n";
if (obj != null)
{
message += "结果：" + obj.ToString();
}
else
{
message += "结果：void";
}
Log.WriteLine(message, "函数结果");
return;
}
else
{
Log.WriteLine("规则名不能为空！", "函数调用错误");
}

}
internal MethodInfo[] GetMethodNames(string strtype)
{
object tdll = assembly.CreateInstance(strtype);
//重新生成报错dll被占用
MethodInfo[] methodInfos = tdll.GetType().GetMethods(BindingFlags.Public|BindingFlags.Instance );
return methodInfos;
}
}

GetMethodNames调用这个函数之后再次重新编译dll 还是报错dll被占用 暂时放弃这个方法不用