使用右击菜单列表的删除删除dgvShow选中的行（dgvShow没有绑定数据库是通过List<Stu>加载数据的）

Question

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace 窗体值传递
{
    public partial class FrmShow : Form
    {
        List<Stu> listStu = null;
        FrmMain fMain = null;
        DataTable dt = null;

        int rowIndex = 0;

        public FrmShow(FrmMain fMain)
        {
            this.fMain = fMain;
            InitializeComponent();
            listStu = new List<Stu>();
            listStu.Add(new Stu("貂蝉", "女", "20"));
            listStu.Add(new Stu("张飞", "男", "22"));
            listStu.Add(new Stu("曹操", "男", "23"));
            listStu.Add(new Stu("吕布", "男", "12"));
            listStu.Add(new Stu("荀彧", "男", "23"));
        }

        private void FrmShow_Load(object sender, EventArgs e)
        {
            this.dgvShow.DataSource = listStu;
        }

        private void btnTest_Click(object sender, EventArgs e)
        {
            Stu s = null;
            this.dt = new DataTable();
            this.dt.Columns.Add("sName", Type.GetType("System.String"));
            this.dt.Columns.Add("sSex", Type.GetType("System.String"));
            this.dt.Columns.Add("sAge", Type.GetType("System.String"));
            //int j = 0;
            for (int i = 0; i < this.dgvShow.RowCount; i++)
            {
                bool re_value = (bool)dgvShow.Rows[i].Cells[0].EditedFormattedValue;
                //判断勾选的
                if (re_value)
                {
                    string sName = this.dgvShow.Rows[i].Cells[1].Value.ToString();
                    string sSex = this.dgvShow.Rows[i].Cells[2].Value.ToString();
                    string sAge = this.dgvShow.Rows[i].Cells[3].Value.ToString();
                    this.dt.Rows.Add(new object[] { sName, sSex, sAge });
                }
            }
            if (this.dt != null)
            {
                //传递到主窗体，更新数据
                this.fMain.Chang(this.dt);
                //foreach (DataRow item in dt.Rows)
                //{
                //    //this.fMain.AddRow(item);
                //    MessageBox.Show(item["sName"].ToString()+","+item["sSex"].ToString()+","+item["sAge"].ToString());
                //}
                this.Close();
            }
        }

        private void tsmi_Del_Click(object sender, EventArgs e)//右击菜单列表的删除
        {
            this.rowIndex = this.dgvShow.CurrentRow.Index;
            MessageBox.Show("Test:" + this.rowIndex.ToString());
            /*
             * 以下执行删除算法
             *
             * */
            //使用右击菜单列表的删除删除dgvShow选中的行（dgvShow没有绑定数据库是通过List<Stu>加载数据的）
            if (dgvShow != null && dgvShow.CurrentCell != null && dgvShow.CurrentCell.RowIndex != -1)
            {
                dgvShow.Rows.RemoveAt(dgvShow.CurrentCell.RowIndex);
            } //报错

            //dgvShow.Rows.RemoveAt(rowIndex);
        }

        private void dgvShow_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            this.rowIndex = e.RowIndex;
            bool re_value = (bool)dgvShow.Rows[this.rowIndex].Cells[0].EditedFormattedValue;
            if (!re_value)
            {
                this.dgvShow.Rows[this.rowIndex].Cells[0].Value = true;
            }
            else
            {
                this.dgvShow.Rows[this.rowIndex].Cells[0].Value = false;
            }
        }

        private void dgvShow_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                if (e.RowIndex >= 0)
                {
                    dgvShow.ClearSelection();
                    dgvShow.Rows[e.RowIndex].Selected = true;
                    //MessageBox.Show("Test:" + e.RowIndex.ToString());

                    //string i = dgvShow.SelectedCells[0].Value.ToString();
                    //MessageBox.Show(i);
                    dgvShow.CurrentCell = dgvShow.Rows[e.RowIndex].Cells[e.ColumnIndex];
                    contextMenuStrip.Show(MousePosition.X, MousePosition.Y);
                }
            }
        }
    }
}