C#winform问题 datagridview中combobox选项改变触发事件用哪个方法

给ComboBox挂事件即可：
        void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
        {
            DataGridView dataGridView = (DataGridView)sender;
            if (dataGridView.CurrentCell.GetType().Name == "DataGridViewComboBoxCell")
            {
                ComboBox comboBox = (ComboBox)e.Control;
                comboBox.SelectedIndexChanged += new EventHandler(comboBox_SelectedIndexChanged);
            }
        }
        void comboBox_SelectedIndexChanged(object sender, EventArgs e)
        {
            ComboBox comboBox = (ComboBox)sender;
            MessageBox.Show(string.Format("选中：{0}", comboBox.Text));
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            DataGridViewComboBoxColumn newColumn = new DataGridViewComboBoxColumn();
            newColumn.Items.Add("下拉项1");
            newColumn.Items.Add("下拉项2");
            newColumn.Items.Add("下拉项3");
            dataGridView1.Columns.Add(newColumn);
            dataGridView1.EditingControlShowing += new DataGridViewEditingControlShowingEventHandler(dataGridView1_EditingControlShowing);