C# form, how can I to solve my EventHandler problem?

Question

I am doing a C# form application, I use a timer and every 10 seconds I have to refresh a datagridview with the elements of a list of list (it may happens that some elements of this list can be removed or others added from another function), in each row of this DataGridView I have to add a CellClick event, the problem is that after each update I add an eventHandler to each row and therefore there are multiple eventListener on every row. When the timer runs out I called the following function:

private void Refresh(object sender, EventArgs e)
        {
             tabUsers.Rows.Clear();
             tabUsers.AutoGenerateColumns = false;
             for (int i = 0; i < list1.Count; i++){
                 tabUsers.CellClick += grd_CellClick;
                 tabUsers.Rows.Add(list1[i][0], list1[i][1], list1[i][2])
             } 
        }

grd_CellClick is the event funcion.

Answer 1

You are attaching grd_CellClick as an event handler every refresh. This is unnecessary, just can configure this event handler once (in the constructor of your form).