Asp.net 设置上下文键时是否不触发Ajax自动完成？

我试图传递一个额外的参数，这样当用户从下拉列表中选择一个状态时，带有autocomplete的文本框将只显示它=所选状态的结果。由于某种原因，添加此函数时，函数getcompletionlist没有启动

Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.ComponentModel
Imports System.Data.SqlClient

' To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the            following   line.
<System.Web.Script.Services.ScriptService()> _
 <System.Web.Services.WebService(Namespace:="http://tempuri.org/")> _
 <System.Web.Services.WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
 <ToolboxItem(False)> _
Public Class AutoComplete1
Inherits System.Web.Services.WebService

<WebMethod()> _
Public Function GetCompletionList(prefixText As String, count As Integer, Contextkey As String) As String()
    Try
        Dim Con As SqlConnection
        Dim cmd As SqlCommand
        Con = New SqlConnection
        'Dim test As String
        'test = Contextkey
        Con.ConnectionString = ""
        Con.Open()

        cmd = New SqlCommand
        cmd.Connection = Con
        cmd.CommandText = "SELECT NPI, [Entity Type Code], [Provider Last Name (Legal Name)], [Provider First Name], [Provider Business Mailing Address City Name] FROM NPIData WHERE [Provider Last Name (Legal Name)] LIKE @Provider + '%'"
        cmd.Parameters.AddWithValue("@Provider", prefixText)
        Dim customers As List(Of String) = New List(Of String)
        Dim reader As SqlDataReader = cmd.ExecuteReader()

        While reader.Read
            customers.Add(reader("Provider Last Name (Legal Name)").ToString + ", " + reader("Provider First Name").ToString + ", " + reader("Provider Business Mailing Address City Name").ToString)

        End While
        Con.Close()

        Return customers.ToArray
    Catch ex As Exception

    End Try

End Function  

End Class

导入System.Web.Services
导入System.Web.Services.Protocols
导入System.ComponentModel
导入System.Data.SqlClient
'要允许使用ASP.NET AJAX从脚本调用此Web服务，请取消注释以下行。
_
_
_
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公共类自动完成1
继承System.Web.Services.WebService
_
公共函数GetCompletionList（prefixText作为字符串，count作为整数，Contextkey作为字符串）作为字符串（）
尝试
Dim Con作为SqlConnection
Dim cmd作为SqlCommand
Con=新的SqlConnection
'将测试设置为字符串
'测试=上下文键
Con.ConnectionString=“”
Con.Open（）
cmd=newsqlcommand
cmd.Connection=Con
cmd.CommandText=“从NPIData中选择NPI，[实体类型代码]，[提供商姓氏（法定名称）]，[提供商名字]，[提供商业务邮寄地址城市名称]，其中[提供商姓氏（法定名称）]，如@Provider+'%'”
cmd.Parameters.AddWithValue（“@Provider”，前缀文本）
将客户作为列表（字符串的）调整=新列表（字符串的）
作为SqlDataReader=cmd.ExecuteReader（）的Dim读取器
边读边读
customers.Add（读卡器（“提供商姓氏（法定名称）”）.ToString+，“+读卡器（“提供商名”）.ToString+，“+读卡器（“提供商业务邮寄地址城市名称”）.ToString）
结束时
Con.Close（）
把顾客退回去
特例
结束尝试
端函数
末级

这是我的aspx自动完成代码：

    <asp:TextBox ID="TextBox1" runat="server" Height="27px" Width="375px"></asp:TextBox>
        <asp:AutoCompleteExtender ID="AutoCompleteExtender" runat="server" 
    DelimiterCharacters="" Enabled="True" ServicePath="AutoComplete.asmx"  
    ServiceMethod="GetCompletionList" TargetControlID="TextBox1" 
    MinimumPrefixLength="2" UseContextKey="true" ContextKey="State">
    </asp:AutoCompleteExtender>

Protected Sub StateDropDown_SelectedIndexChanged(sender As Object, e As EventArgs) Handles        StateDropDown.SelectedIndexChanged
    AutoCompleteExtender.ContextKey = StateDropDown.Text
End Sub

受保护的子状态下拉列表\u SelectedIndexChanged（发件人作为对象，e作为事件参数）处理状态下拉列表。SelectedIndexChanged
AutoCompleteXtender.ContextKey=StateDropDown.Text
端接头

我知道现在评论已经晚了，但请在webmethod中将ContextKey更改为ContextKey，希望它能正常工作

Public Function GetCompletionList(ByVal prefixText As String,ByVal count As Integer,ByVal          contextKey As String) As String()