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

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" Head开发者_StackOverflow中文版erStyle-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>

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).

You can declare a ComboBox mainBX = new Combobox(); and you can declare an event

private void onSeletedIndexChange(object sender,EventArgs e)
{
        mainBX = (ComboBox)(sender);
}

and next you should iterate foreach ComboBox in GridView and Add this Event . Than all you should do is ,take the mainBX.seletedItem();

I think this is what you need ,if not apologise .

To set the Selected Value in the RowDataBound-Event, you should do it like this:

(DropDownList)e.Row.Cells[/*index*/].Controls[/*index, or use FindControl*/]).Items.FindByValue(((DataRowView)e.Row.DataItem).Row.ItemArray[/*columnnumber*/].ToString()).Selected = true;

FindByValue finds the current Textvalue of the Field in the "normal" Viewmode and sets the DropDownList with the value.

Of course this needs to be encapsulated in

if ((e.Row.RowState & DataControlRowState.Edit) == DataControlRowState.Edit)
{
}

As for your "getting the Value at Update"-Problem, I must honestly say I've got no clue, since your approach is exactly like mine, only difference: mine works.

Here's my code if it's any help:

 protected void gridVariables_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {

        string control = ((DropDownList)gridVariables.Rows[e.RowIndex].Cells[3].Controls[1]).SelectedValue;
        gridVariables.EditIndex = -1;
        this.gridVariables_DataBind(control, e.RowIndex);
    }

private void gridVariables_DataBind(string control, int index)
    {
        DataTable dt = (DataTable)Session["variableTable"]; //features a DataTable with the Contents of the Gridview
        dt.Rows[index]["ControlType"] = control;
        gridVariables.DataSource = dt;
        gridVariables.DataBind();
    }

I had the same problem with a different solution, I had implemented custom paging on the GridView with a custom pager, and in the process added the RowCommand method, which was rebinding the grid with a new page index. As it happens though the RowCommand method is also called during Updating.

So be sure to check any other locations you may be binding anywhere in your code. Hope this helps somebody else.

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    string commandName = e.CommandName;

    switch (commandName)
        {
            case "Page1":
                HandlePageCommand(e);
                //binding should happen here
                break;
        }

        //this line is in the wrong location, causing the bug    
        BindGrid1();
}