C# WinForm DataGridView 给标题列增加序号及格式化某个字段

private void dataGridView1_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
        {
            DataGridViewTextBoxColumn dgv_Text = new DataGridViewTextBoxColumn();
            for (int i = 0; i < dataGridView1.Rows.Count; i++)
            {
                int j = i + 1;
                dataGridView1.Rows[i].HeaderCell.Value = j.ToString();
            }
            
        }

private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            if ( e == null || e.Value == null || !(sender is DataGridView) )
            {
                return;
            }
            DataGridView dgv = (DataGridView)sender;
            object originalValue = e.Value;
             
            if(dgv.Columns[e.ColumnIndex].DataPropertyName == "操作类型")
            {
                 e.Value = ((int)originalValue  == 1) ? "缴费" : "退费";
            }
 
            if (e.ColumnIndex == dgv.Columns["Apply_Date"].Index)   //格式化日期
            {
                if (e.Value != null)
                {
                    e.Value = Convert.ToDateTime(e.Value).ToString("yyyy-M-d");
                }
            }

        }