学习计时软件之datagridview刷新的问题

第一种方法：通过添加contextMenuStrip控件来绑定刷新。

第二种方法：将数据库绑定代码重构成方法，然后每调用一次就重新绑定一次。

private void button1_Click(object sender, EventArgs e)
        {
            string sql = "server=5C497A61D1A1484//SQLEXPRESS;database=Time;integrated security=SSPI;";
            //string sql1 = "SELECT [ShenTime]FROM [Time].[dbo].[RY] where [科目]='1'";
          
            SqlConnection con = new SqlConnection(sql);
            con.Open();
            if (textBox1.Text == "")
            {
                MessageBox.Show("请输入完成时数！");
            }
            else
            {
                i = Convert.ToDouble(textBox1.Text);
                j = Convert.ToDouble(dataGridView1.CurrentRow.Cells[0].Value.ToString());
                z = j - i;
               string str = Convert.ToString(z);
              string sql2 = "UPDATE [Time].[dbo].[RY]SET [ShenTime] = '"+str+"'where [科目]='1'";
              SqlCommand cmd = new SqlCommand(sql2, con);
              cmd.ExecuteNonQuery();
              databind();
            }
          
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            databind();
        }

        private void databind()
        {
            string sql = "server=5C497A61D1A1484//SQLEXPRESS;database=Time;integrated security=SSPI;";
            string sql1 = "SELECT [ShenTime]FROM [Time].[dbo].[RY]";
            SqlConnection con = new SqlConnection(sql);
            con.Open();
            SqlDataAdapter da = new SqlDataAdapter(sql1, con);
            DataSet ds = new DataSet();
            da.Fill(ds, "table");
            dataGridView1.DataSource = ds.Tables[0].DefaultView;
            con.Close();
        }