是的，你可以。

HTTP处理程序

public class Class1 : IHttpHandler
    {
        public bool IsReusable => false;

        public void ProcessRequest(HttpContext context)
        {
            Assembly ass = Assembly.LoadFile(context.Request.PhysicalPath);
            Type[] assemblyTypes = ass.GetTypes();
            for (int j = 0; j < assemblyTypes.Length; j++)
            {
                if (assemblyTypes[j].Name == "WebDLL")
                {
                    object o = Activator.CreateInstance(assemblyTypes[j]);
                    MethodInfo mi = assemblyTypes[j].GetMethod("ProcessRequest");
                    mi.Invoke(o, new object[] { context });
                }
            }
        }
    }

动态链接库

public class WebDLL
    {
        public void ProcessRequest(HttpContext context)
        {
            context.Response.Write("Hello World!");
        }
    }

它将输出Hello World！