ASP.NET从背后的EditItemTemplate中的DropDownList获取值

Question

I have a GridView that I have placed in DropDownList's in 2 columns.

 <asp:TemplateField HeaderText="Upgrade" SortExpression="Upgrade">
                <ItemTemplate>
                    <asp:Label ID="LabelUpgrade" runat="server" Text='<%# Eval("Upgrade") %>' />
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:DropDownList ID="ddlUpgrade" runat="server" Width="100px">
                        <asp:ListItem Value="1">--Select--</asp:ListItem>
                        <asp:ListItem Value="2">1</asp:ListItem>
                        <asp:ListItem Value="3">2</asp:ListItem>
                        <asp:ListItem Value="4">3</asp:ListItem>
                        <asp:ListItem Value="5">4</asp:ListItem>
                        <asp:ListItem Value="6">5</asp:ListItem>
                    </asp:DropDownList>
                </EditItemTemplate>
            </asp:TemplateField>

how do I grab the item from ddlUpgrade in the codebehind?

OnUpdating Event - I don't have a way to pull the row to get the value from the drop down but I add my sql parameters here.

 protected void IAP_Updating(object sender, SqlDataSourceCommandEventArgs e){}

RowUpdating Event - I can get the row here but I can't add the value to the sql parameters because e.command isn't valid here

protected void gvClients_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        GridViewRow _row = gvClients.Rows[e.RowIndex];

        DropDownList _ddl = (DropDownList)_row.FindControl("ddlUpgrade");
        SqlParameter _parm = new SqlParameter("@Upgrade", _ddl.SelectedItem.ToString());
    }

Answer 1

On the RowUpdating event you can capture the control inside the edit template based on its ID.

GridViewRow row = GridView1.Rows[e.RowIndex];

DropDownList ddl = (DropDownList)row.FindControl("ddlUpgrade");

SqlParameter _parm = new SqlParameter("@Upgrade", ddl.SelectedItem.ToString());
    e.Command.Parameters.Add(_parm);

Answer 2

I would add a hidden field outside the GridView:

<asp:HiddenField ID="hdnSelection" value="" runat="server" />

And change the gvClients_RowUpdating method:

protected void gvClients_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow _row = gvClients.Rows[e.RowIndex];        
    DropDownList _ddl = _row.FindControl("ddlUpgrade") as DropDownList;

    if(_ddl != null)
    {
        hdnSelection.Value = _ddl.SelectedItem.Text;
        IAP.Update();//Assuming IAP is the ID of the SqlDataSource
    }

}

And my IAP_Updating method should look like this:

protected void IAP_Updating(object sender, SqlDataSourceCommandEventArgs e)
{
    SqlParameter _parm = new SqlParameter("@Upgrade", hdnSelection.Value);
    e.Command.Parameters.Add(_parm);
}

I did not test the code. You may need to tweak.