/// <summary>
        /// 编辑用户
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnEditClick(object sender, EventArgs e)
        {
            //1收集网格上旧的数据源
            var curUser = _userList.Single(c => c.Id == listBoxUser.SelectedValue.ToString());

            //2手机用户修改后的信息
            var formUserInfo = new FormRegister(curUser.Id, curUser.Name, curUser.Password);
            var dialogResult = formUserInfo.ShowDialog();
            if (dialogResult != DialogResult.OK) return;

            //3校验信息
            var user = _userList.Single(c => c.Id == curUser.Id);

            if (curUser.Id != formUserInfo.UserInfo.Id &&
                _userList.Any(c=>c.Id==formUserInfo.UserInfo.Id))
            {
                MessageBox.Show(@"用户编号已存在,请重新修改。");
                return;
            }

            //4保存信息
            user.Id = formUserInfo.UserInfo.Id;
            user.Name = formUserInfo.UserInfo.Name;
            user.Password = formUserInfo.UserInfo.Password;

            bindingSource1.ResetCurrentItem();                  //通过数据源组件重设当前项
        }
        /// <summary>
        /// 新增用户
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnAddClick(object sender, EventArgs e)
        {
            //1获取User对象
            var formUserInfo = new FormRegister();
            var dialogResult = formUserInfo.ShowDialog();
            if (dialogResult != DialogResult.OK) return;
            var userInfo = formUserInfo.UserInfo;

            //2验证数据
            if (_userList.Any(user => user.Id == userInfo.Id))
            {
                MessageBox.Show(@"新增失败,用户编号已经存在!");
                return;
            }

            if (_userList.Any(user => user.Name == userInfo.Name))
            {
                MessageBox.Show(@"新增失败,用户姓名已经存在!");
                return;
            }

            //3通过数据绑定组件同步界面和数据源
            bindingSource1.Add(userInfo);
        }