Problems with dynamic buttons in ASP.NET (C#)

The event handler for dynamic controls need to be registered during Page_Load / Page_Init events to be triggered (see this link).

So, You have to add your Delete button and its event handler in page_load or init. to find ID of the control which cause postback in Page_Init event, see this

UPDATE:

OK, i add this code to proof it can be done without problems.

To see how it works: create a new Web Form and paste the following HTML & Code-Behinds into it. Then run the app and type some name in Search TextBox (eg: John or Ali) and press Search Button to filter the results.

public partial class _Default : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string searchName = "";
        if (SearchTextBox.Text != "") //if (this.GetPostBackControlUniqueID() == Search.UniqueID) //Search button is clicked! 
        {
            searchName = SearchTextBox.Text;
        }
        addTable(searchName);
    }

    void addTable(string searchName)
    {
        string[] data = new[] { 
             "John, false, usrJohn"
            ,"Alex, false, usrAlex"
            ,"Ali,  true,  usrAli" 
        };

        //using (OleDbDataReader reader = cmd.ExecuteReader())
        //{
            Table table = new Table(); table.CellPadding = 10;
            TableRow row;
            TableCell cell;
            Label label;

            foreach(string dataItem in data) //while (reader.Read())
            {
                string[] reader = dataItem.Split(',');
                if (reader[0].IndexOf(searchName, StringComparison.OrdinalIgnoreCase) < 0) continue; //search not found (in real app, you use sql where clause for this, but this is just for test)

                row = new TableRow();
                cell = new TableCell();
                label = new Label();

                label.Text = reader[0].Trim(); //reader.GetString(0);
                cell.Controls.Add(label);
                cell.BorderStyle = BorderStyle.Solid;
                row.Cells.Add(cell);

                cell = new TableCell();
                label = new Label();

                label.Text = reader[1].Trim(); //reader.GetBoolean(1).ToString();
                cell.Controls.Add(label);
                cell.BorderStyle = BorderStyle.Solid;
                row.Cells.Add(cell);

                cell = new TableCell();
                LinkButton button = new LinkButton();

                button.Text = "Delete";
                string uName = reader[2].Trim();
                button.ID = uName; //(string)reader["uName"];
                button.CommandName = uName; //(string)reader["uName"];
                button.Click += new EventHandler(DeleteUser);

                cell.Controls.Add(button);
                cell.BorderStyle = BorderStyle.Solid;
                row.Cells.Add(cell);

                table.Rows.Add(row);
            }

            table.Style.Add(HtmlTextWriterStyle.MarginLeft, "auto");
            table.Style.Add(HtmlTextWriterStyle.MarginRight, "auto");

            TableHolder.Controls.Add(table);
        //} //end using OleDbDataReader reader
    }

    protected void Search_Click(object sender, EventArgs e)
    {
        //addTable(SearchTextBox.Text); //already done in Page_Load
    }

    protected void DeleteUser(object sender, EventArgs e)
    {

        LinkButton button = (LinkButton)sender;
        //using (OleDbCommand cmd = new OleDbCommand("DELETE * FROM ArcadeDatabase WHERE uName ='" + button.CommandName + "';", con))
        string sql = "DELETE * FROM ArcadeDatabase WHERE uName ='" + button.CommandName + "';";
        //execute the sql ... (in real app)

        TableHolder.Controls.Add(new LiteralControl("The sql was: " + sql));
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        Label1.Text = DateTime.Now.ToString("HH:mm:ss");
    }


} //end class

And this is the helper extension method to Get UniqueID of PostBack Control:

// ***********************************************************************
public static class MyWebPageExtensions
{

    public static string GetPostBackControlUniqueID(this Page page)
    {
        if (!page.IsPostBack)
            return string.Empty;

        Control control = null;

        string controlName = page.Request.Params["__EVENTTARGET"]; //this method works only for link buttons which use javascript: __doPostBack(...) and not input type=submit buttons. Note: it is also available in Request.Form collection but this doesn't require to loop over Form.
        if (!String.IsNullOrEmpty(controlName))
        {
            control = page.FindControl(controlName);
        }
        else
        {
            // __EVENTTARGET is null, the control is a button (not javascript linkButton), we need to iterate over the form collection to find it
            foreach (string id in page.Request.Form)
            {
                // handle ImageButton they having an additional "quasi-property" in their Id which identifies mouse x and y coordinates
                if (id.EndsWith(".x") || id.EndsWith(".y"))
                {
                    string id2 = id.Substring(0, id.Length - 2);
                    control = page.FindControl(id2);
                }
                else
                {
                    control = page.FindControl(id);
                }

                if (control is IButtonControl) break;

            }
        }

        return control == null ? String.Empty : control.UniqueID;
    }

}