Getting te ID of a Selected Item in a dropdownlist.

[Rob Venable]

Hi all,
Can anyone tell me how to retrieve the ID of a selected item from a
DropDownList. My query brings back the ID and value and I cycle through
the .Read Method to add items to the DropDownList.
e.g.
While dr.Read
DDL.Items.Add(dr("value"))
End While

I can do it if I use this method:
DDL.DataSource = dr
DDL.DataTextField = "value"
DDL.DataValueField = "id"
DDL.DataBind()

and then refer the the DataValueField to get the ID.

This would be the easy way but I have to do it by adding items to the
DDL.
Is there a property I can set to make it equal to the ID and then be
able to retrieve it?

Thanks

Rob
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[Ken Cox [Microsoft MVP]]

Hey Rob,

Is it adding the list items to the ddl that is giving you trouble? If so,
here's a way to add them via the reader and display the ID when the ddl is
changed.

Private Sub Page_Load _
(ByVal sender As System.Object, _
ByVal e As System.EventArgs) _
Handles MyBase.Load
If Not IsPostBack Then
Dim myCMD As SqlCommand = _
New SqlCommand _
("SELECT CategoryID, CategoryName FROM Categories", _
SqlConnection1)
SqlConnection1.Open()
Dim dr As SqlDataReader = myCMD.ExecuteReader()
Dim lstItem As ListItem
While dr.Read
lstItem = New ListItem
lstItem.Text = dr.Item("CategoryName")
lstItem.Value = dr.Item("CategoryID")
DropDownList1.Items.Add(lstItem)
End While
dr.Close()
SqlConnection1.Close()
End If
End Sub
Private Sub DropDownList1_SelectedIndexChanged _
(ByVal sender As Object, ByVal e As System.EventArgs) _
Handles DropDownList1.SelectedIndexChanged
Label1.Text = DropDownList1.SelectedItem.Value.ToString
End Sub

<P>
<asp:DropDownList id="DropDownList1" runat="server"
AutoPostBack="True"></asp:DropDownList></P>
<P>
<asp:Label id="Label1" runat="server">Label</asp:Label></P>
Ken
MVP [ASP.NET]

"Rob Venable" <rv******@rogers.com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl...

Hi all,
Can anyone tell me how to retrieve the ID of a selected item from a
DropDownList. My query brings back the ID and value and I cycle through
the .Read Method to add items to the DropDownList.
e.g.
While dr.Read
DDL.Items.Add(dr("value"))
End While

I can do it if I use this method:
DDL.DataSource = dr
DDL.DataTextField = "value"
DDL.DataValueField = "id"
DDL.DataBind()

and then refer the the DataValueField to get the ID.

This would be the easy way but I have to do it by adding items to the
DDL.
Is there a property I can set to make it equal to the ID and then be
able to retrieve it?

Thanks

Rob
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[Rob Venable]

Thanks Ken,
That works fine but I still have one little problem. I need to add a
blank entry in my dropdownlist because this select box is not a
mandatory field on my form.
If I instantiate the listitem inside my while loop, how can I add a
blank line at the top?

Thanks for your help.

Rob

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[Marshal Antony]

Rob,

This is the code you need.

DropDownlist.Items.Insert(0,new ListItem(" "," "));

This will add a blank item to the first position of the drop down list.

Ragards,

Marshal Antony

http://dotnetmarshal.com


"Rob Venable" <rv******@rogers.com> wrote in message
news:%2***************@TK2MSFTNGP12.phx.gbl...

Thanks Ken,
That works fine but I still have one little problem. I need to add a
blank entry in my dropdownlist because this select box is not a
mandatory field on my form.
If I instantiate the listitem inside my while loop, how can I add a
blank line at the top?

Thanks for your help.

Rob

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[Rob Venable]

Thanks Marshal,

That's exactly what I needed.

Regards,
Rob
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