ASP.Net：元素<名称>不是已知元素

Question

我一直在尝试使用 ASP.NET Ajax Control Toolkit 中的 AutoComplete Extender，但是在让它实际工作时遇到了很多麻烦。

为了安装 AjaxControlToolKit，我将其放置在应用程序的 bin 目录中，然后将控件拖放到表单中。 然而，它一直说，

“元素‘AutoCompleteExtender’不是一个已知元素”

所以一开始，我以为我还没有注册它，但是当我查看标题时，它已经在那里了：

<%@ Register Assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35" Namespace="System.Web.UI" TagPrefix="asp" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" tagprefix="ajaxToolkit"%>

所以我不确定总而言之，为什么它仍然给我带来问题。

我的 bin 文件夹中的其他程序集文件包括：

System.Web.Extensions.ddl System.Web.Extensions.Design.dll

这是我的代码：

<asp:TextBox ID="txtOrganization" runat="server" Width ="500px" MaxLength ="250"></asp:TextBox>
<asp:ScriptManager ID="ScriptManager1" runat="server">
    <Services>
        <asp:ServiceReference Path="AutoComplete.asmx" />
    </Services>
</asp:ScriptManager>
<ajaxToolkit:AutoCompleteExtender runat="server" TargetControlID="txtOrganization" ServiceMethod="GetOrganizationList" ServicePath="AutoComplete.asmx"></ajaxToolkit:AutoCompleteExtender>

Answer 1

我修好了它并让它工作。 我必须更改我的 aspx 页面和 web.config。

ASPX：
将其添加到我的页面顶部：

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" tagprefix="ajaxToolkit"%>

我的控件现在看起来像这样：

        <asp:TextBox ID="txtOrganization" runat="server" Width ="500px" MaxLength ="250"></asp:TextBox>
        <asp:ScriptManager ID="ScriptManager1" runat="server" >
            <Services>
                <asp:ServiceReference Path="AutoComplete.asmx" />
            </Services>
        </asp:ScriptManager>
        <ajaxToolkit:AutoCompleteExtender runat="server" ID="AutoComplete1" 
                                          TargetControlID="txtOrganization" 
                                          ServicePath="AutoComplete.asmx" ServiceMethod="GetOrganizationList"
                                          MinimumPrefixLength="1" EnableCaching="true"
                                          FirstRowSelected="true">
        </ajaxToolkit:AutoCompleteExtender>

至于我的 web.config，我添加了以下内容：

<configSections>
    <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
        <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
            <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
            <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
                <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere"/>
                <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
                <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
            </sectionGroup>
        </sectionGroup>
    </sectionGroup>
</configSections>

<system.web>
    <pages>
        <controls>
            <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        </controls> 
    </pages>
    <customErrors mode="Off"/>
    <compilation debug="true" strict="false" explicit="true">
        <assemblies>
            <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
            <add assembly="System.Web.Extensions.Design, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
            <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
            <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        </assemblies>               
    </compilation>
    <httpHandlers>
        <remove verb="*" path="*.asmx"/>
        <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
    </httpHandlers>
    <httpModules>
        <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </httpModules>
    <sessionState mode="InProc" cookieless="false" timeout="240"/>
    <!--
        The <authentication> section enables configuration 
        of the security authentication mode used by 
        ASP.NET to identify an incoming user. 
    -->
    <authentication mode="Forms"/>
    <!--
        The <customErrors> section enables configuration 
        of what to do if/when an unhandled error occurs 
        during the execution of a request. Specifically, 
        it enables developers to configure html error pages 
        to be displayed in place of a error stack trace.

    <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
        <error statusCode="403" redirect="NoAccess.htm" />
        <error statusCode="404" redirect="FileNotFound.htm" />
    </customErrors>
    -->
    <httpRuntime maxRequestLength="16000" useFullyQualifiedRedirectUrl="true" executionTimeout="180"/>
</system.web>
<system.web.extensions>
    <scripting>
        <webServices>
            <!-- Uncomment this line to customize maxJsonLength and add a custom converter -->
            <!--
  <jsonSerialization maxJsonLength="500">
    <converters>
      <add name="ConvertMe" type="Acme.SubAcme.ConvertMeTypeConverter"/>
    </converters>
  </jsonSerialization>
  -->
            <!-- Uncomment this line to enable the authentication service. Include requireSSL="true" if appropriate. -->
            <!--
    <authenticationService enabled="true" requireSSL = "true|false"/>
  -->
            <!-- Uncomment these lines to enable the profile service. To allow profile properties to be retrieved
       and modified in ASP.NET AJAX applications, you need to add each property name to the readAccessProperties and
       writeAccessProperties attributes. -->
            <!--
  <profileService enabled="true"
                  readAccessProperties="propertyname1,propertyname2"
                  writeAccessProperties="propertyname1,propertyname2" />
  -->
        </webServices>
        <!--
  <scriptResourceHandler enableCompression="true" enableCaching="true" />
  -->
    </scripting>
</system.web.extensions>
<system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules>
        <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </modules>
    <handlers>
        <remove name="WebServiceHandlerFactory-Integrated"/>
        <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </handlers>
</system.webServer>

本来，由于我使用的是asp.net 2.0，System.Web.Extensions的版本号是1.6....所以我不得不将其全部更改为3.5.0.0。

另外，在寻找解决方案时，很多人说我必须将 System.Web.Extensions.dll 和 System.Web.Extensions.Design.dll 的副本放入 bin 文件夹中。 我不必这样做，我只是添加了对它们的引用。

Answer 2

您是否为项目添加了对它的引用？
在 Visual Studio 中右键单击项目...点击“属性”
在参考资料旁边，您应该会看到 AjaxControlToolkit...
如果没有，请点击“添加...”进入“浏览”选项卡并选择它。

我假设没有其他控件起作用？

Answer 3

您是否在页面顶部放置了 ScriptManager？ 您必须执行此操作才能使 Toolkit 控件正常工作。

编辑：导致此问题的潜在原因有很多； 您没有正确安装 AJAX 工具包、您的站点存在编译错误等。较常见的问题之一是您需要在 web.config 文件中声明该工具包。 在页面标签内，添加以下内容：

<controls>
<add tagPrefix="ajaxToolkit" namespace="AjaxControlToolkit" assembly="AjaxControlToolkit"/>
</controls>