I have a repeater with a dropdownlist in it. When a user changes its index, I would like a label to change its value. (the ddlSizes values come from a MySQL DB)
Sizes.aspx
<asp:DropDownList ID="ddlSizes" runat="server" AutoPostBack="True" DataSourceID="objdsSizes" DataTextField="SizeName" DataValueField="SizeID" />
<asp:Label ID="lbldummy" runat="server" Text=""></asp:Label>
Sizes.aspx.vb
Protected Sub ddlSizes_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlSizes.SelectedIndexChanged
lbldummy = ddlSizes.value
End Sub
But the ddlSizes.SelectedIndexChanged isn't recognized. So the value of lbldummy
won't change.
Any suggestions? Thank you.
You will want to create the handler for the DropDownList
, within this you need to have code which will convert the sender into a DropDownList
then get the parent control and convert it into the RepeaterItem
. From this you can then reference any other controls within the RepeaterItem
Public Sub ddlSizes_SelectedIndexChanged(sender As Object, e As EventArgs)
Dim ddlSizes As DropDownList = DirectCast(sender, DropDownList)
Dim ri As RepeaterItem = DirectCast(ddlSizes.Parent, RepeaterItem)
Dim lbldummy As Label = DirectCast(ri.FindControl("lbldummy"), Label)
lbldummy.Text = ddlSizes.SelectedValue
End Sub
Then on your ddlSizes DropDownList add OnSelectedIndexChanged="ddlSizes_SelectedIndexChanged"
and make sure it has AutoPostBack="True" set
Text is probably the default property, but I'd still specify it:
lbldummy.Text = ddlSizes.value
but for this, you really don't need to do a postback, you can accomplish this through Javascript as well. doing something like this:
<asp:DropDownList ID="ddlSizes" runat="server" onchange="return ddlSizes_change(this);" DataSourceID="objdsSizes" DataTextField="SizeName" DataValueField="SizeID" />
function ddlSizes_change(dropdown)
{
document.getElementById('<%= lbldummy.ClientID %>').innerHTML =
dropdown.options[myindex].value
return true;
}
Here's an example (C# but easily adaptable to VB.NET). Notice how inside the DdlSizes_SelectedIndexChanged
I use FindControl
to find the corresponding label:
<%@ Page Language="C#" %>
<script type="text/c#" runat="server">
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
rep.DataSource = Enumerable.Range(1, 5);
rep.DataBind();
}
}
protected void DdlSizes_SelectedIndexChanged(object sender, EventArgs e)
{
var ddl = (DropDownList)sender;
var lbl = (Label)ddl.FindControl("lbldummy");
lbl.Text = ddl.SelectedValue;
}
</script>
<!DOCTYPE html>
<html>
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="Form1" runat="server">
<asp:Repeater ID="rep" runat="server">
<ItemTemplate>
<asp:DropDownList ID="ddlSizes" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DdlSizes_SelectedIndexChanged">
<asp:ListItem Value="1" Text="item 1" />
<asp:ListItem Value="2" Text="item 2" />
<asp:ListItem Value="3" Text="item 3" />
</asp:DropDownList>
<asp:Label ID="lbldummy" runat="server" />
</ItemTemplate>
</asp:Repeater>
</form>
</body>
</html>