How can I get the selected value from dropdownlist in edit mode of a gridview?

Question

In my application, when I edit a row in the gridview I choose some new data from a dropdownlist.

I am populating the dropdown like this:

 protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            if ((e.Row.RowState & DataControlRowState.Edit) > 0)
            {
                DropDownList emailsListDL = (DropDownList)e.Row.FindControl("emailsDL");
                emailsListDL.DataSource = allUsersEmails;//list of strings with the emails of the users
                emailsListDL.DataBind();
            }
        }
    }

But when I press the 'Update' button from the template and enters in the 'RowUpdating' event, the selected value from the dropdownlist is every time the first value from that dropdownlist.

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        DropDownList emailsListDL = (DropDownList)GridViewAdvertisers.Rows[e.RowIndex].FindControl("emailsDL");
        string email = emailsListDL.SelectedValue; //the selected value is every time the first value from the dropdownlist
    }

Does anyone have any ideas?

I've tried many ways to set the selected value in the 'RowDataBound' event, but with no luck. I tried this:

1. emailsListDL.SelectedIndex = emailsListDL.Items.IndexOf(emailsListDL.Items.FindByValue(DataBinder.Eval(e.Row.DataItem, "OwnerMail").ToString()));
2. emailsListDL.SelectedValue = GridViewAdvertisers.DataKeys[e.Row.RowIndex]["OwnerMail"].ToString();
3. emailsListDL.SelectedValue = GridViewAdvertisers.Rows[e.Row.RowIndex].Cells[1].Text;
//ownerMail is a string (object) from the list of objects that I put as datasource to the gridview

Thanks, Jeff

Update

My Item template from the aspx page is:

 <asp:TemplateField ItemStyle-HorizontalAlign="Center" ItemStyle-VerticalAlign="Middle"
                ItemStyle-Width="150px" HeaderText="Owner Email" HeaderStyle-HorizontalAlign="Left"
                HeaderStyle-BorderWidth="1px" HeaderStyle-BorderColor="#e1e1e1">
                <ItemTemplate>
                    <asp:Label ID="LabelEmail" runat="server" Text='<%# Bind("OwnerMail")%>'></asp:Label>
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:DropDownList ID="emailsDL" runat="server" Width="150">
                    </asp:DropDownList>
                </EditItemTemplate>
                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Font-Bold="True"></HeaderStyle>
                <ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Width="180px" BorderWidth="1px"
                    BorderColor="#e1e1e1"></ItemStyle>
    </asp:TemplateField>

Answer 1

The SelectedIndex will always default to 0 if you don't define it in your DropDownList definition.

Edit: @Tim Schmelter should add his comment as an anwer. In the meantime, I'll paraphrase for other readers: You need to check for postback (see comments above).