I need to get the value of a drop down list in an asp gridview when updating the row

Question

Everything should work, but i can't figure out why i can't get the value from the ddl. I know the code is not too clean.

protected void gridProduse_RowEditing(object sender, GridViewEditEventArgs e)
    {
        gridProduse.EditIndex = e.NewEditIndex;
        gridProduse.DataBind();


        using (var context = new SATContext())
        {
            var query = from t in context.TipuriProduse
                        select t.Denumire;
            DropDownList list = new DropDownList();
            list.DataSource = query.ToList();
            list.DataBind();
            list.ID = "ddlTipProdus";
            list.Height = 27;
            DropDownList listMoneda = new DropDownList();
            listMoneda.ID = "ddlMoneda";
            listMoneda.Items.Add("RON");
            listMoneda.Items.Add("EUR");
            listMoneda.Items.Add("USD");
            listMoneda.Height = 27;
            gridProduse.Rows[e.NewEditIndex].Cells[7].Controls.Add(list);
            gridProduse.Rows[e.NewEditIndex].Cells[6].Controls.Add(listMoneda);
            gridProduse.Rows[e.NewEditIndex].Cells[6].Controls[0].Visible = false;
            gridProduse.Rows[e.NewEditIndex].Cells[7].Controls[0].Visible = false;
        }
    }

    protected void gridProduse_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        GridViewRow row = gridProduse.Rows[e.RowIndex];
        Produs prod = new Produs();
        prod.ProdusId = Convert.ToInt32(((TextBox)(row.Cells[2].Controls[0])).Text);
        prod.Denumire = ((TextBox)(row.Cells[3].Controls[0])).Text;

        DropDownList ddl = (DropDownList)gridProduse.Rows[e.RowIndex].FindControl("ddlMoneda");
        prod.Moneda = ddl.SelectedValue; // this is where i get the error
        //prod.Moneda = ((row.FindControl("ddlMoneda") as DropDownList)).SelectedValue;
        prod.PretCuTVA = Convert.ToInt32(((TextBox)(row.Cells[5].Controls[0])).Text);
        prod.PretFaraTVA = Convert.ToInt32 (((TextBox)(row.Cells[4].Controls[0])).Text);
        lit1.Text = prod.ProdusId.ToString();
        using (var context = new SATContext())
        {
            IRepository<Produs> ProdusRepository = new ProdusRepository();
            ProdusRepository.Update(prod);
        }
        gridProduse.EditIndex = -1;
        gridProduse.DataBind();

        Response.Redirect("Produse.aspx");
    }

And this is the error:

An exception of type 'System.NullReferenceException' occurred in Licenta.dll but was not handled in user code

Additional information: Object reference not set to an instance of an object.

I guess there is no `SelectedValue` at the moment. Are you sure a row or item is selected? — Afzaal Ahmad Zeeshan, Jun 13 '15 at 20:32
possible duplicate of [What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Hamid Pourjam, Jun 13 '15 at 20:33
Yes, I'm pretty sure it is selected. And I know what NullReferenceException is, I just can't figure out why it doesn't work... — Andrei Mișcu, Jun 13 '15 at 20:35
It looks like your `ddl` variable is null, not the SelectedValue. Are you sure that FindControl returns the correct result? — DanielS, Jun 13 '15 at 20:45
Indeed, ddl is null. Any idea then on how to get to the control? — Andrei Mișcu, Jun 13 '15 at 20:52

DarkNinja955 · Answer 1 · 2015-06-14T17:14:34.650

0

~~I'm pretty sure that you need to select a cell before you can reliably call `FindControl'~~

(DropDownList)gridProduse.Rows[e.RowIndex].Cells[SomeCell].FindControl("ddlMoneda");

Since your listMoneda control is being created dynamically after the Page_Init event, it is not being registered in the ViewState, and thus cannot be found on PostBack. Read this explanation for a solution

edited Jun 14 '15 at 17:14

answered Jun 13 '15 at 21:08

DarkNinja955

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8

I need to get the value of a drop down list in an asp gridview when updating the row

1 Answers1