Question

In the code below the SelectionChanged event is fired before the end of RowsAdded,how can I make the Event atomic?

private void dataGridView1_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)
    {
        dataGridView1.CurrentCell = dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells[1];
        dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells[1].Selected = true;
    }

private void dataGridView1_SelectionChanged(object sender, EventArgs e)
    {
        if (dataGridView1.CurrentRow != null)
        {
            //Something
        }
    }

what should i do?

Answer 1

SelectionChanged is fired in the middle of handling RowsAdded because you are causing a SelectionChanged by changing the current cell within dataGridView1_RowsAdded. Adding a row doesn’t cause both events to be fired — you’re causing the second event while handling the first one. (In fact, you’re probably causing SelectionChanged twice, because both lines in the handler seem to change the selection).

If you don’t want dataGridView1_SelectionChanged running while in the RowsAdded handler, you need to either temporarily unsubscribe from the event:

dataGridView1.SelectionChanged -= dataGridView1_SelectionChanged;
// change the selection... 
dataGridView1.SelectionChanged += dataGridView1_SelectionChanged;

Or even better, re-design what you’re doing inside the SelectionChanged handler so that it is appropriate for all instances of the event.