Trouble binding value from a cascading drop down

Question

5.00/5 (1 vote)

See more:

I have cascading drop down boxes that appear to be working - BUT when I try to bind the displayed text I somehow bind the ID associated with the displayed text.

I don't know if the problem is in my webservice or in the way I bind the data. If anyone has any ideas I would really appreciate it.

My Web Method:

WebMethod(); _
Public Function GetProcedure(ByVal knownCategoryValues As String, ByVal category As String) As CascadingDropDownNameValue()
       Dim strConnection As String = ConfigurationManager.ConnectionStrings("WPSConnectionString").ConnectionString
       Dim sqlConn As SqlConnection = New SqlConnection(strConnection)
       Dim strProcQuery As String = "SELECT  [Procedure], ProcID from Proc_Procedure where SubCategoryID = @SubCategoryID"
       Dim cmdFetchProc As SqlCommand = New SqlCommand(strProcQuery, sqlConn)

       Dim dtrProc As SqlDataReader
       Dim kvProc As StringDictionary = CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues)

       Dim SubCategoryId As Integer

       If Not kvProc.ContainsKey("SubCategory") Or Not Int32.TryParse(kvProc("SubCategory"), SubCategoryId) Then
           Return Nothing
       End If

       cmdFetchProc.Parameters.AddWithValue("@SubCategoryID", SubCategoryId)

       Dim myProc As New List(Of CascadingDropDownNameValue)

       sqlConn.Open()
       dtrProc = cmdFetchProc.ExecuteReader

       While dtrProc.Read()
           Dim strProcName As String = dtrProc("Procedure").ToString
           Dim strProcId As Integer = dtrProc("ProcID")

           myProc.Add(New CascadingDropDownNameValue(strProcName, strProcId))
       End While

       Return myProc.ToArray
   End Function

My data binding:

<asp:DropDownList ID="ddlprocedure" runat="server"
     SelectedValue='<%# bind("Procedure") %>' DataTextField="Procedure" DataValueField="ProcID">
     </asp:DropDownList>
     <asp:CascadingDropDown ID="ddlprocedure_cdd" runat="server"
     TargetControlID="ddlprocedure"
     Category="Procedure"
     PromptText="Select Procedure"
     LoadingText="Please wait..."
     ServicePath="~/ProcedureService.asmx"
     ServiceMethod="GetProcedure"
     ParentcontrolID="ddlSubCategory">
     </asp:CascadingDropDown>

     </InsertItemTemplate>
     <ItemTemplate>
     <asp:Label ID="Label1" runat="server" Text='<%# Bind("Procedure") %>'></asp:Label>

Posted 9-Dec-09 6:53am

JaredShaw

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

JaredShaw · Answer 1 · 2009-12-10T05:44:00

I figured out a work-around for my issue.

I bound the data from my cascading drop down extender instead of the drop down control itself. This data appeared as the ID followed by ":::" followed by the text value (ex. 13:::sometext)

To deal with that, I created an onindexchange sub on the drop down box that uses indexof and substring to pull out the text I want - and then sets the final value to a session variable.

Then I modified my insert and update parameter fields for my detailsview to use a session parameter instead of a regular parameter for the affected field.

Nobody is going to call it elegant, but it gets the job done.

   Private Sub proc_trim(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim ddlvar As CascadingDropDown = CType(DetailsView1.FindControl("ddlprocedure_cdd"), CascadingDropDown)
        Dim sbad As String = ddlvar.SelectedValue
        If sbad.IndexOf(":::") < 0 Then
            Session("clean_proc") = sbad
        Else
            Dim i As Integer = sbad.IndexOf(":::")
            Dim smid As String = sbad.Substring(i)
            Dim sneed As String = smid.Substring(3)
            Session("clean_proc") = sneed
        End If
    End Sub


.....

<asp:DropDownList ID="ddlprocedure" runat="server" OnSelectedIndexChanged="proc_trim" 
DataTextField="Procedure" DataValueField="Procedure">
</asp:DropDownList>
<asp:CascadingDropDown ID="ddlprocedure_cdd" runat="server" 
           TargetControlID="ddlprocedure"
           Category="Procedure"
           PromptText="Select Procedure"
           LoadingText="Please wait..."
           ServicePath="~/ProcedureService.asmx"
           ServiceMethod="GetProcedure"
           ParentcontrolID="ddlSubCategory">      
</asp:CascadingDropDown>

.....

<InsertParameters>
<asp:SessionParameter Name="procedure" SessionField="clean_proc" Type="String" />
</InsertParameters>