How to determine which button is clicked in dynamically created DataTable - asp.net

Question

I'm creating dynamically data Table bound to Grid View. Every row is populated with button. When i determine which button is clicked on the row, i want to get the current value of cell in clicked button in that row and modify her.Help!
Markup
<asp:GridView ID="GridView2" runat="server"
OnRowDataBound="GridView2_RowDataBound">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:Button ID="btnTest" runat="server"
CommandName="odzemi"
CssClass="button2"
Font-Bold="True"
Text="-"
Width="100px"
OnClick="btnTest_Click" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
//in this way a create row
private void AddNewRecordRowToGrid()
{
int counter;
if (Request.Cookies["kasa"] == null)
counter = 0;
else
{
counter = int.Parse(Request.Cookies["kasa"].Value);
}
counter++;
Response.Cookies["kasa"].Value = counter.ToString();
Response.Cookies["kasa"].Expires = DateTime.Now.AddYears(2);
if (ViewState["Markici"] != null)
{
DataTable dtCurrentTable = (DataTable)ViewState["Markici"];
DataRow drCurrentRow = null;
if (dtCurrentTable.Rows.Count > 0)
{
for (int i = 1; i <= dtCurrentTable.Rows.Count; i++)
{
HttpCookie cookie = Request.Cookies["Democookie"];
drCurrentRow = dtCurrentTable.NewRow();
drCurrentRow["FirmaID"] = Request.Cookies["firma"].Value;
drCurrentRow["Godina"] = Request.Cookies["godina"].Value;
drCurrentRow["KasaID"] = Request.Cookies["kasa"].Value;
drCurrentRow["MarkicaID"] = Request.Cookies["kasa"].Value;
drCurrentRow["Datum"] = DateTime.Now;
drCurrentRow["Masa"] = Session["masa39"];
drCurrentRow["VrabotenID"] = Session["New"];
drCurrentRow["Artikal"] = Label3.Text;
drCurrentRow["Cena1"] = Label4.Text;
//this is where i need to make changes
drCurrentRow["Kolicina"] = Label5.text;
drCurrentRow["Smena"] = Session["smena1"];
drCurrentRow["VkIznos"] = Label6.Text;
drCurrentRow["VkDanok"] = Label8.Text;
drCurrentRow["SySDatum"] = DateTime.Now;
drCurrentRow["Vid"] = Label23.Text;
drCurrentRow["Edmera"] = Label10.Text;
drCurrentRow["ArtikalID"] = Label33.Text;
}
//Removing initial blank row
if (dtCurrentTable.Rows[0][0].ToString() == "")
{
dtCurrentTable.Rows[0].Delete();
dtCurrentTable.AcceptChanges();
}
//Added New Record to the DataTable
dtCurrentTable.Rows.InsertAt(drCurrentRow,0);
//storing DataTable to ViewState
ViewState["Markici"] = dtCurrentTable;
//binding Gridview with New Row
GridView2.DataSource = dtCurrentTable;
GridView2.DataBind();
}
}
}
//in this button i call that method
protected void Button9_Click(object sender, EventArgs e)
{
AddNewRecordRowToGrid();
}
//
and here i'm determine clicked button of row, and here in this
dtCurrentTable.Rows[clickedIndex]["Kolicina"]= "" i need to
get cureent value of cell which is different in every row.
protected void btnTest_Click(object sender, EventArgs e)
{
DataTable dtCurrentTable = (DataTable)ViewState["Markici"];
var clickedRow = ((Button)sender).NamingContainer as GridViewRow;
var clickedIndex = clickedRow.RowIndex;
//so here i want to get current value of cell, and modify her
dtCurrentTable.Rows[clickedIndex]["Kolicina"] = " ";
GridView2.DataSource = dtCurrentTable;
GridView2.DataBind();
}

Answer 1

Try this.
protected void btnTest_Click(object sender, EventArgs e)
{
var clickedRow = ((Button)sender).NamingContainer as GridViewRow;
var clickedIndex = clickedRow.RowIndex;
}
Provided your GridView does not have sorting or paging enabled, from this clickedIndex, we can get the corresponding Row of the DataTable like this.
dtCurrentTable.Rows[clickedIndex]["Kolicina"] = "StackOverflow";

Answer 2

In the RowDataBound event, the EventArgument e should have the index of the current item bound in it. The code e.Row.RowIndex will return the index of the row in the Grid, not necessarily the datasource when you have paging applied. There is a 'DataItemIndex' property, another index that may give you what you are looking for, depending on what you are trying to do.
The grid also exposes the Rows collection, which you can use a foreach to loop through each one, and access that way too.
Note, the Rows on postback will only be based on the markup posted back through viewstate; the grid knows nothing about your data source (unless you rebind on every postback).