ASP.NET - Get DropDownList SelectedValue for current Row when using RowCommand

Question

• When I run the row command event from a button on a gridview row I can detect the correct value from any field found on the eventrow.

• hidID which is a unique identifier reports correctly for each row as expected.

• ddlVal always reports the first item in the list and not the currently selected value.

• Can anyone offer explanation as to why a dropdownlist would not detect the currently selected value when using the command event?

---

ASP.NET

  <asp:GridView ID="gv" runat="Server" AutoGenerateColumns="False" OnRowCommand="gv_RowCommand" EnableModelValidation="False">
    <Columns>
      <asp:TemplateField HeaderText="Reason Missed" ItemStyle-CssClass="Inline" HeaderStyle-CssClass="NoSort" Visible="false">
        <ItemTemplate>
          <asp:DropDownList ID="ddl" runat="server" DataSourceID="sqldatasource" DataValueField="ID" DataTextField="Text" AppendDataBoundItems="true">
            <asp:ListItem Text="Select ..." Value="0"/>
          </asp:DropDownList>
        </ItemTemplate>
      </asp:TemplateField>
    </Columns>
  </asp:GridView>

<asp:SqlDataSource ID="sqldatasource" runat="Server" SelectCommand="sp" SelectCommandType="StoredProcedure"/>

---

VB

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
  Dim constring = ConfigurationManager.ConnectionStrings("Con").ConnectionString
  sqldatasource.ConnectionString = constring

  Bind_gv()
End Sub

Protected Sub gv_RowCommand(sender As Object, e As GridViewCommandEventArgs)
  Dim rowIndex As Integer = Convert.ToInt32(e.CommandArgument)
  Dim row As GridViewRow = gv.Rows(rowIndex)
  Dim ddlVal As Integer = DirectCast(row.FindControl("ddl"), DropDownList).SelectedValue
  Dim hidID As Integer = DirectCast(row.FindControl("hidID"), HiddenField).Value
  'ETC ...
End Sub

Answer 1

After some further diagnosis I found that:

• The row command event first reloads the page.
• This triggers the pages life cycle.
• The RowCommand event is triggered after the Page_Load event.
• The RowCommand event is triggered before PreRender event.

The consequences of this are if you bind data in the Page_Load event then this data is bound/rebound before the RowCommand is trigger.

If, like I was in my case, you are binding your dropdownlist in the Page_Load event or binding the gridview and a sqldatasource in the Page_Load then any clientside changes will be lost prior to the RowCommand being triggered as they will reset to their initial values.

ANSWER

Bind your gridview in any event after the RowCommand fires such as OnPreRenderComplete. This way clientside changes will still be available up until the RowCommand event is triggered.