DataGridView CellLeave未触发

Question

我有一个问题，即datagridview_CellLeave事件没有被触发，我在网上搜索了这个问题，但我没有找到任何关于它的信息，请你帮忙吗？以下是我的代码。

        /**
     * dataGridView1_CellLeave() method
     * Find sum and populate third cell. 
     */
    private void dataGridView1_CellLeave(object sender, DataGridViewCellEventArgs e)
    {
        Console.Write("Cell Leave entry");

        int sum = 0;

        if (e.ColumnIndex == 0) //if second cell
        {
            sum = Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[1].Value) *
                  Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[2].Value);

            dataGridView1.Rows[e.RowIndex].Cells[3].Value = sum;
            MessageBox.Show("Cell Leave sum: " + sum);
        }
    } //dataGridView1_CellLeave