Rows.Count with dropdown list

Question

Using .net 4 and c# I'm trying to get data from database into GridView and display the number of rows returned. I also have a dropdown list used as ControlParameters in SqlDataSource to filter results.

This works fine on initial page load, but when I select something from the dropdown the results are filtered, but rows count doesn't change. When I select another item from the dropdown, the rows count gets updated but with the number correct for the previous value.

        <h5> Showing <asp:Label ID="WOs_count" runat="server" Text="Label"></asp:Label> Work Orders.</h5>  

        <asp:DropDownList 
            ID="DropDownList1" 
            runat="server" 
            AutoPostBack="True">
            <asp:ListItem Value="%">All requests</asp:ListItem>
            <asp:ListItem Value="BBTeam">BB Team</asp:ListItem>
        </asp:DropDownList>

The Select statement:

 <asp:SqlDataSource 
    ID="WorkList" 
    runat="server" 
    ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
    SelectCommand="SELECT TASKS.WOID AS wo_id, Tasks.Completed AS 'Completed Date', Tasks.Respons AS 'Technician', FROM Tasks WHERE (Tasks.Completed>=DATEADD(day,-60,GETDATE())OR Tasks.Completed IS NULL)  AND (Tasks.Respons LIKE @Respons)  ">
    <SelectParameters>
        <asp:ControlParameter name="Respons" ControlID="DropDownList1" PropertyName="SelectedValue"/>
    </SelectParameters>

</asp:SqlDataSource>

Then in the code behind I have this:

        protected void Page_Load(object sender, EventArgs e)
    {

        WOs_count.Text = WO_list.Rows.Count.ToString();
    }

I'm completely new to .net so wouldn't be surprised if I miss something obvious.

Answer 1

I think your issue is that the Page_Load event is firing before the grid is re-binding to the data, which is why the count is always one postback behind.

You could try updating the count in a later Page event, like OnPreRender(object sender, EventArgs e) or updating the count in the DataBound event on your Grid View...

Add this to your ASPX :

 <asp:GridView ID="WO_list" runat="server" OnDataBound="WO_list_DataBound" ... />

and then add this to the Code Behind (C#):

protected void WO_list_DataBound(EventArgs e){ WOs_count.Text = WO_list.Rows.Count.ToString(); }

Give this a try and let me know if either/both work.

Answer 2

This should fix it for you.

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {  
        WOs_count.Text = WO_list.Rows.Count.ToString();
    }