Ajax调用不访问Partial Class

Question

当前代码仅在我删除部分类（Def）并通过公共类名称（PatientRegistration）调用AJAX时才有效

请帮助

Imports System.Configuration
Imports System.Data.SqlClient
Imports System.Data
Imports System.Web.Configuration
Imports System.IO
Imports System.Drawing
Imports System.Collections.Generic
Imports System.Threading
Imports System.Globalization
Imports System
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports AjaxControlToolkit
Imports System.Web.Services
Imports Microsoft.VisualBasic


Public Class PatientRegistration
Inherits System.Web.UI.Page
Partial Class Def
    Inherits System.Web.UI.Page
     <System.Web.Services.WebMethod()> _
    Public Shared Sub JSTblRegReadRec(ByVal FileNum As String)
        MsgBox(FileNum)
    End Sub
End Class

<script>
       function JSTblRegReadRec() {
           $.ajax({
               type: 'POST',
               url: "Def.aspx/JSTblRegReadRec",
               data: '{FileNum: "' + $("#<%=FilenumSel.ClientID%>")[0].value + '" }',
               contentType: "application/json; charset=utf-8"
           })
           .success(function (response) {
               alert(response.d);
           })
                   .error(function (response) {
                       alert(response.d);
                   });
       }
         
   </script>

当前代码仅在我删除部分类（Def）并通过公共类名称（PatientRegistration）调用AJAX时才有效

谢谢！