First from the DataGridView property, change "AllowUserToAddRows" from "True" to "False"
Changed Snippets:
Change "row = dataGridView1.Rows.Count -2;" to "row = dataGridView1.Rows.Count -1;" in your methods.
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if (e.RowIndex > -1)
{
var curCell = dataGridView1.CurrentCell;
if (curCell.Value == null || (bool)curCell.Value == false)
{
curCell.Value = true;
}
else
{
curCell.Value = false;
}
if ((bool)curCell.Value)
{
dataGridView1.Columns["AMOUNT"].Visible = true;
}
else
{
dataGridView1.Columns["AMOUNT"].Visible = false;
}
}
}
If this works, please mark this as a solution.