If Datalist returns no data, then ...

[MojoZig]

Got a simple question, if I have this datalist below that gets populated via a sql database.

            <asp:DataList ID="DataList1" runat="server" DataSourceID="SqlDataSource1" BackColor="LightGoldenrodYellow" BorderColor="Tan" BorderWidth="1px" CellPadding="2" ForeColor="Black">
                <ItemTemplate>
                    <br />
                    Account:
                    <asp:Label ID="AccountLabel" runat="server" Text='<%# Eval("Account") %>'></asp:Label><br />
                    Name:
                    <asp:Label ID="NameLabel" runat="server" Text='<%# Eval("Name") %>'></asp:Label><br />
                    Amount:
                    <asp:Label ID="AmountLabel" runat="server" Text='<%# Eval("Amount", "{0:C}") %>'></asp:Label><br />
                    &nbsp;<br />
                    <asp:HiddenField ID="HFAccount" runat="server" Value='<%# Eval("Account") %>' />
                    <asp:HiddenField ID="HFName" runat="server" Value='<%# Eval("Name") %>' />
                    <asp:HiddenField ID="HFAmount" runat="server" Value='<%# Eval("Amount") %>' />
                </ItemTemplate>
                <FooterStyle BackColor="Tan" />
                <SelectedItemStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
                <AlternatingItemStyle BackColor="PaleGoldenrod" />
                <HeaderStyle BackColor="Tan" Font-Bold="True" />
            </asp:DataList>

How do I write the codebehind to response.write("That account number is invalid!") if no data is returned?

Would I use ItemCreated or ItemDatabound?

Would it be something like (which I know is incorrect):

    Protected Sub DataList1_ItemCreated(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataListItemEventArgs) Handles DataList1.ItemCreated

        If DataList1 Is Nothing Then
        Response.Write("That Account Number was not found, please check it and try again!")

        End If
    End Sub

 

[firstdivision]

If you don't get any items back then ItemCreated or ItemDatabound won't run (or at least not run with ItemType Item or Alternating Item?).

In any case, I guess the easiest way would be to check the item count after you bind the datalist, so something like

Datalist1.DataSource = ...
Datalist1.Databind

If DataList1.Items.Count = 0 then
   Response.Write("That Account Number was not found!")
End If

 

[BoulderBum]

In your case, you probably want to add a handler for a SqlDataSource event, namely "Selected", and do the above in there.

 

[MojoZig]

Thanks for the replies. I really appreciate your time. I have a few questions, please excuse the lack of knowledge on my part.

My SqlDataSource is "SqlDataSource1" for the DataSourceID for DataList1.

So, knowing that: when you say DataList.Datasource = ... does "..." represent my datasource of SqlDataSource1?

If so, It gets underlined with an error saying it can't converted to a string and then the page error states that both DataSource and DataSourceID are both present. so I changed DataSource to DataSourceID ... is this incorrect? It does gets rid of that error but then gets the other about can't be converted to a string.

I did created the handler for the SqlDataSource1 and put the code there.

    Protected Sub SqlDataSource1_Selected(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.SqlDataSourceStatusEventArgs) Handles SqlDataSource1.Selected

        'DataList1.DataSourceID = SqlDataSource1
        'DataList1.DataBind()

        If DataList1.Items.Count = 0 Then
            lblNoAccount.Text = ("That Account Number was not found!")

        End If
    End Sub

If I rem out the first two lines, the label gets the text value whether it returns data or not ...

Do you see the error, cause I certainly don't!? Thanks again, Most Appreciative! Suggestions? Thoughts? )

 

[MojoZig]

I think I figured it out! Let me know if you know why this couldn't be done this way:

    Protected Sub SqlDataSource1_Selected(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.SqlDataSourceStatusEventArgs) Handles SqlDataSource1.Selected
        If e.AffectedRows = 0 Then
        lblNoAccount.Text = ("That Account Number was not found!")

        End If
    End Sub

It seems to work properly ... and I totally stumbled upon it by accident using what you both told me to do. Do either of you see any proplems with e.AffectedRows = 0??

Let me know your thoughts and I really appreciate your time on helping me out!