如何让AjaxControlToolKit的AjaxFileUpload支持所有文件类型及无扩展名文件？

我需要让AjaxControlToolKit的AjaxFileUpload控件支持上传所有文件类型，但尝试了以下代码后未能生效，恳请各位提供帮助：

<ajaxToolkit:AjaxFileUpload ID="AjaxFileUploader" runat="server" Width="100%" Style="padding-bottom: 10px" OnClientUploadStart="UploadStart" OnClientUploadCompleteAll="UploadEnd" AllowedFileTypes="*" AutoStartUpload="True"/>

按照Albert D. Kallal的建议修改后，我的配置文件和控件标记如下：

修改后的web.config内容：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <sectionGroup name="devExpress">
      <section name="themes" type="DevExpress.Web.ThemesConfigurationSection, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
      <section name="compression" type="DevExpress.Web.CompressionConfigurationSection, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
      <section name="settings" type="DevExpress.Web.SettingsConfigurationSection, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
      <section name="errors" type="DevExpress.Web.ErrorsConfigurationSection, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
      <section name="resources" type="DevExpress.Web.ResourcesConfigurationSection, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
      <section name="bootstrap" type="DevExpress.Web.Bootstrap.BootstrapConfigurationSection, DevExpress.Web.Bootstrap.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
    </sectionGroup>
    <section name="ajaxControlToolkit" type="AjaxControlToolkit.AjaxControlToolkitConfigSection, AjaxControlToolkit" requirePermission="false" />
  </configSections>
  <ajaxControlToolkit additionalUploadFileExtensions="dcm," />
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <handlers>
      <add name="AjaxFileUploadHandler" verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler,AjaxControlToolkit" />
      <add type="DevExpress.Web.ASPxHttpHandlerModule, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" verb="GET,POST" path="DX.ashx" name="ASPxHttpHandlerModule" preCondition="integratedMode" />
      <add type="DevExpress.Web.ASPxUploadProgressHttpHandler, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" verb="GET,POST" path="ASPxUploadProgressHandlerPage.ashx" name="ASPxUploadProgressHandler" preCondition="integratedMode" />
    </handlers>
    <modules runAllManagedModulesForAllRequests="true">
      <add type="DevExpress.Web.ASPxHttpHandlerModule, DevExpress.Web.v22.2, Version=22.2.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" name="ASPxHttpHandlerModule" />
    </modules>
    <staticContent>
      <mimeMap fileExtension=".dcm" mimeType="application/dicom" />
    </staticContent>
  </system.webServer>
  <appSettings>
  bla bla bla bla

修改后的控件标记：

<ajaxToolkit:AjaxFileUpload ID="AjaxFileUploader" runat="server" Width="100%" Style="padding-bottom: 10px" OnClientUploadStart="UploadStart" OnClientUploadCompleteAll="UploadEnd" AllowedFileTypes="dcm,zip" AutoStartUpload="True"/>

内容的提问来源于stack exchange，提问作者ranasrule