int r = 0;
        string c = "";
        DataSet ds = new DataSet();



        private void button1_Click(object sender, EventArgs e)
        {
            DataSet ds = new DataSet();

            if (skey.Text.Trim() == "")
            {
                MessageBox.Show("请输入分类名称", "提示");
                return;
            }

            string strConnect = Properties.Settings.Default.PopInfoConnectionString;
            SqlConnection conConnection = new SqlConnection(strConnect);
            conConnection.Open();
            string cmd = " select classname as 产品分类名称,uptime as 最后更新日期 from [zmlb] where classname='" + skey.Text.Trim() + "'";
            SqlDataAdapter ada = new SqlDataAdapter(cmd, conConnection);
            ada.Fill(ds);
            dataGridView1.DataSource = ds.Tables[0];
        }


        private void dataGridView1_RowEnter(object sender, DataGridViewCellEventArgs e)
        {
            r = e.RowIndex; /*获得具有焦点的行*/
            c = dataGridView1.Rows[r].Cells[1].Value.ToString();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            dataGridView1.Rows.RemoveAt(r);
        }


        private void dataGridView1_RowsRemoved(object sender, DataGridViewRowsRemovedEventArgs e)
        {
            string strConnect = Properties.Settings.Default.PopInfoConnectionString;
            SqlDataAdapter ada = new SqlDataAdapter();
            SqlConnection conConnection = new SqlConnection(strConnect);
            SqlCommand com = new SqlCommand("Delete From zmlb Where classname=@x", conConnection);

            com.Parameters.Add("@x", SqlDbType.Char, 10);
            com.Parameters[0].Value = c; /*对数据库进行操作的参数添加*/
            ada.DeleteCommand = com;
            ada.Update(ds);
        }

public int UpdateByDataSet(DataSet ds,string strTblName,string strConnection)
{
   try
  {
   SqlConnection  conn = new SqlConnection(strConnection));
   SqlDataAdapter myAdapter = new SqlDataAdapter();
   SqlCommand myCommand = new SqlCommand("select * from "+strTblName),(SqlConnection)this.conn);   
   myAdapter.SelectCommand = myCommand;
   SqlCommandBuilder myCommandBuilder = new SqlCommandBuilder(myAdapter);    
   myAdapter.Update(ds,strTblName); 
   return 0;
  }
  catch(BusinessException errBU)
  { 
   throw errBU;
  }  
  catch(Exception err)
  { 
   throw new BusinessException(err);
  }
}

private void button2_Click(object sender, EventArgs e)
{
  dataGridView1.Rows.RemoveAt(r);
  UpdateByDataSet(dataGridView1.DataSource as DataTable,"zmlb",Properties.Settings.Default.PopInfoConnectionString);
}

------解决方案--------------------
C# code

private void dataGridView1_RowsRemoved(object sender, DataGridViewRowsRemovedEventArgs e)
        {
//...
com.ExecuteNonQuery();//加一句执行删除的就可以了
ada.Update(ds);
}

------解决方案--------------------
请不要高估你的描述能力或者我的理解能力。

------解决方案--------------------
if (DataGridView.IsCurrentCellDirty) DataGridView.CommitEdit(DataGridViewDataErrorContexts.Commit);
xx.Update(xx)