DataGridView增加欄位

DataGridViewTextBoxColumn col5 = new DataGridViewTextBoxColumn();
dataGridView1.Columns.Add(col5);
dataGridView1.Columns[5].Name = "Column5";
DataGridViewTextBoxColumn col6 = new DataGridViewTextBoxColumn();
dataGridView1.Columns.Add(col6);
dataGridView1.Columns[6].Name = "Column6";