将生成的出勤详细信息添加到Database asp.net c＃

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;

public partial class UserAttendance : System.Web.UI.Page
{
    SqlConnection vid = new SqlConnection("Data Source=DESKTOP-430E2O0\\SQLEXPRESS;Initial Catalog=mca;Integrated Security=True");
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Calendar1.Visible = true;
        TextBox1.Visible = true;
        String str = "select * from Student where (Course like '%' + @search + '%')";
        String str1 = "select * from Student where (Semester like '%' + @search + '%')";
        SqlCommand xp = new SqlCommand(str, vid);
        SqlCommand xp1 = new SqlCommand(str1, vid);
        xp.Parameters.Add("@search", SqlDbType.NVarChar).Value = DropDownList1.SelectedItem.Text;
        xp1.Parameters.Add("@search", SqlDbType.NVarChar).Value = DropDownList2.SelectedItem.Text;
        vid.Open();
        xp.ExecuteNonQuery();
        xp1.ExecuteNonQuery();
        SqlDataAdapter da = new SqlDataAdapter();
        da.SelectCommand = xp;
        da.SelectCommand = xp1;
        DataSet ds = new DataSet();
        da.Fill(ds, "Course");
        da.Fill(ds, "Semester");
        GridView1.DataSource = ds;
        GridView1.DataBind();
        vid.Close();
        Button2.Visible = true;
    }
    protected void Calendar1_SelectionChanged(object sender, EventArgs e)
    {
        TextBox1.Text = Calendar1.SelectedDate.ToShortDateString();
        Calendar1.Visible = false;

    }
    protected void Button2_Click(object sender, EventArgs e)
    { 
       //I wish to use this button to save details to the database
    }

       
}

<%@ Page Title="" Language="C#" MasterPageFile="~/User.master" AutoEventWireup="true" CodeFile="UserAttendance.aspx.cs" Inherits="UserAttendance" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
    <style type="text/css">
        .auto-style1 {
            width: 100%;
        }
        .auto-style2 {
            width: 179px;
        }
        .auto-style3 {
            width: 6px;
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <form id="form1" runat="server">
        <table class="auto-style1">
            <tr>
                <td class="auto-style2">
                    <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:studentConnectionString %>" SelectCommand="SELECT [Course] FROM [Course]"></asp:SqlDataSource>
                </td>
                <td>
                    <asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1" DataTextField="Course" DataValueField="Course">
                    </asp:DropDownList>
                    <asp:DropDownList ID="DropDownList2" runat="server" DataSourceID="SqlDataSource2" DataTextField="Semester" DataValueField="Semester">
                    </asp:DropDownList>
                    <asp:DropDownList ID="DropDownList3" runat="server" DataSourceID="SqlDataSource3" DataTextField="Subject" DataValueField="Subject">
                    </asp:DropDownList>
                    <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="OK" Width="49px" />
                </td>
                <td class="auto-style3">&nbsp;</td>
            </tr>
            <tr>
                <td class="auto-style2">
                    &nbsp;</td>
                <td>
                    <asp:Calendar ID="Calendar1" runat="server" OnSelectionChanged="Calendar1_SelectionChanged" Visible="False"></asp:Calendar>
                </td>
                <td class="auto-style3">&nbsp;</td>
            </tr>
            <tr>
                <td class="auto-style2">
                    &nbsp;</td>
                <td>
                    <asp:TextBox ID="TextBox1" runat="server" Visible="False"></asp:TextBox>
                </td>
                <td class="auto-style3">&nbsp;</td>
            </tr>
            <tr>
                <td class="auto-style2">
                    <asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:studentConnectionString %>" SelectCommand="SELECT [Semester] FROM [Semester]"></asp:SqlDataSource>
                </td>
                <td>
                    <asp:GridView ID="GridView1" runat="server" CellPadding="4" ForeColor="#333333" GridLines="None">
                        <AlternatingRowStyle BackColor="White" />
                        <Columns>
                            <asp:TemplateField>
                                <ItemTemplate>
                                    <asp:DropDownList ID="DropDownList4" runat="server">
                                        <asp:ListItem>Present</asp:ListItem>
                                        <asp:ListItem>Absent</asp:ListItem>
                                        <asp:ListItem>Holiday</asp:ListItem>
                                    </asp:DropDownList>
                                </ItemTemplate>
                            </asp:TemplateField>
                        </Columns>
                        <EditRowStyle BackColor="#2461BF" />
                        <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                        <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                        <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
                        <RowStyle BackColor="#EFF3FB" />
                        <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
                        <SortedAscendingCellStyle BackColor="#F5F7FB" />
                        <SortedAscendingHeaderStyle BackColor="#6D95E1" />
                        <SortedDescendingCellStyle BackColor="#E9EBEF" />
                        <SortedDescendingHeaderStyle BackColor="#4870BE" />
                    </asp:GridView>
                </td>
                <td class="auto-style3">&nbsp;</td>
            </tr>
            <tr>
                <td class="auto-style2">
                    <asp:SqlDataSource ID="SqlDataSource3" runat="server" ConnectionString="<%$ ConnectionStrings:studentConnectionString %>" SelectCommand="SELECT [Subject] FROM [Subject]"></asp:SqlDataSource>
                </td>
                <td style="text-align: justify">
                    <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Save" Visible="False" Width="58px" />
                </td>
                <td class="auto-style3">&nbsp;</td>
            </tr>
        </table>
    </form>
</asp:Content>
<asp:Content ID="Content3" ContentPlaceHolderID="ContentPlaceHolder2" Runat="Server">
</asp:Content>

我有一个包含日期的文本框（Gridview外面） 我在gridview中有一个下拉列表作为模板字段（Absent / Present） 我在网格视图外面有一个名为“save”的按钮 当我按下保存按钮时，详细信息应该转到数据库，并应保存在表格中。 出勤表的列 1.ID 2.Name 3.Course 4.Semester 5.Date 6.Status（缺席/礼物）