combo problem

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Dec 18th, 2002, 09:06 AM
venerable bede

combo problem

(Dreamweaver MX, ASP.NET, VB.NET)

I have an edit page which uses a combo box.

The user chooses an item from the combo and the value is written away to the underlying field.

The problem I have is that everytime the user goes to the webpage the 1st item is always displayed.

Is there any way I can check to see if there is a value in the underlying field and if there is force the combo to jump to that item.

Thanksin advance
Dec 18th, 2002, 10:09 AM
HumanCompiler

If you enable viewstate (.EnableViewState = True) and make sure that you're only filling the DropDownList the first time the page loads (If Not IsPostBack Then), then it will stay on the last item you selected, which is what you're going for, right?
Dec 18th, 2002, 10:28 AM
venerable bede

I'm not sure about this.

WHen the user first goes to the page, lets say the underlying field contains "3" which refers to the 3rd item in the combo I want the combo to display the text representing the third item.

I'll have to apologise but I'm new to all this .net code.
Dec 18th, 2002, 01:04 PM
HumanCompiler

I'm sorry, but I'm not following what you're asking for.

You know about the .DataTextField and .DataValueField properties, right?

VB Code:

<script language="vb" runat="server">
Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim myExistingValue As String = "item2"
    If myExistingValue <> "" Then
        If Not myDropDownList.Items.FindByValue(myExistingValue) Is Nothing Then        
            myDropDownList.Items.FindByValue(myExistingValue).Selected = True
        End If
    End If
End Sub 
</script>
<html>
  <body>
    <form id="SelectAnItem" runat="server">
        <asp:DropDownList
            ID="MyDropDownList"
            Runat="server">
            <asp:ListItem Value="item1">item1</asp:ListItem>    
            <asp:ListItem Value="item2">item2</asp:ListItem>
            <asp:ListItem Value="item3">item3</asp:ListItem>
        </asp:DropDownList>
    </form>
  </body>
</html>

change it to this...the changed lines are bold

VB Code:

<script language="vb" runat="server">
Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
    [b]If Not IsPostBack Then[/b]
        Dim myExistingValue As String = "item2"
        If myExistingValue <> "" Then
            If Not myDropDownList.Items.FindByValue(myExistingValue) Is Nothing Then        
                myDropDownList.Items.FindByValue(myExistingValue).Selected = True
            End If
        End If
    [b]End If[/b]
End Sub 
</script>
<html>
  <body>
    <form id="SelectAnItem" runat="server">
        <asp:DropDownList
            ID="MyDropDownList"
            Runat="server"
            [b]AutoPostBack="True">[/b]
            <asp:ListItem Value="item1">item1</asp:ListItem>    
            <asp:ListItem Value="item2">item2</asp:ListItem>
            <asp:ListItem Value="item3">item3</asp:ListItem>
        </asp:DropDownList>
    </form>
  </body>
</html>

The way you had it, it would set the selected item to "item2" every time and would never change.