Search for the first letter of a word using keyboard input in data grid view

My question is how to search for a word's start with a letter which is given by keyboard. I did this using the code below.

Now I want to do this for the next row. Once I find a word, I want to go to the next row by clicking the down arrow. But开发者_如何转开发 when I click the down arrow, the selected row goes to the previous selected row.

How can I solve this?

if (Char.IsLetterOrDigit(e.KeyChar))
{
    if (Char.IsLetter(e.KeyChar))
    {
        for (int i = 0; i < (dgvTestHead.Rows.Count); i++)
        {
            if (dgvTestHead.Rows[i].Cells["Test_Head"].Value.ToString()
                .StartsWith(e.KeyChar.ToString(),
                            true,
                            CultureInfo.InvariantCulture))
            {
                dgvTestHead.ClearSelection();
                dgvTestHead.Rows[i].Cells[0].Selected = true;
                dgvTestHead.FirstDisplayedScrollingRowIndex = i;
                dgvTestHead.Refresh();

                return; // stop looping
            }
        }
    }
}

I think it happens because the CurrentRow property of the DataGridView doesn't change. To set the CurrentRow to the selected row (it is read-only), use:

dgvTestHead.CurrentCell = dgvTestHead.Rows[i].Cells[0];

this worked for me.