How to get Dynamically Generated Controls value and store it into databse if controls generated on any postback

See more:

C#

ASP.NET

SQL

server

Hello ,
Please help me to find solution for this problem

What i have-
1.
i have a page which have some dropdownlist controls and on selectedIndexChanged event i call a method in which some dynamic controls are generated.

these controls are 2 labes and one text box

2.
on any buttonClick event i want to get labels and textbox value and stored it into database



What My Problem-
i am unable to get values of dynamically generated controls...


My Code is-
On Aspx Page

<table>
    <tr>
        <td>
            <table>
                <tr>
                    <td>Select Subject</td>
                    <td>
                        <asp:DropDownList ID="ddlSubject" runat="server">
                        </asp:DropDownList>
                    </td>
                    <td>Select Class</td>
                    <td>
                        <asp:DropDownList ID="ddlClass" runat="server" AutoPostBack="true"
                            onselectedindexchanged="ddlClass_SelectedIndexChanged">
                        </asp:DropDownList>
                    </td>
                    <td>Select Section</td>
                    <td>
                        <asp:DropDownList ID="ddlSection" runat="server" AutoPostBack="true"
                            onselectedindexchanged="ddlSection_SelectedIndexChanged">
                        </asp:DropDownList>
                    </td>
                </tr>
            </table>
        </td>
    </tr>
</table>
<br />
<div id="studentList"  runat="server"></div>
<asp:Button ID="btnSubmit" Text="Submit" OnClick="btnSubmit_Click" runat="server" />

On Aspx.cs

protected void ddlSection_SelectedIndexChanged(object sender, EventArgs e)
    {
        bindStudents();
    }
    protected void ddlClass_SelectedIndexChanged(object sender, EventArgs e)
    {
        bindStudents();
    }
    public void bindStudents()
    {
        qry = "select * from Student_info where class='" + ddlClass.SelectedValue.ToString() + "' AND section='" + ddlSection.SelectedValue.ToString() + "'";
        SqlCommand cmd = new SqlCommand(qry, con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        con.Close();


        Table table = new Table();
        table.Attributes["class"] = "dynamic_table";
        studentList.Controls.Add(table);

        TableRow trh = new TableRow();

        TableCell tch1 = new TableCell();
        Label lblIdHeader = new Label();
        lblIdHeader.Text = "Student_Id";
        tch1.Controls.Add(lblIdHeader);

        TableCell tch2 = new TableCell();
        Label lblTitleHeader = new Label();
        lblTitleHeader.Text = "Student_Name";
        tch2.Controls.Add(lblTitleHeader);

        TableCell tch3 = new TableCell();
        Label lblMarksHeader = new Label();
        lblMarksHeader.Text = "Marks";
        tch3.Controls.Add(lblMarksHeader);

        trh.Cells.Add(tch1);
        trh.Cells.Add(tch2);
        trh.Cells.Add(tch3);
        table.Rows.Add(trh);
        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
        {
            TableRow tr = new TableRow();

            TableCell td1 = new TableCell();
            Label lblId = new Label();
            //lblId.ID = "lbl_" + ds.Tables[0].Rows[i]["Id"].ToString();
            lblId.ID = "lblId_" + i;
            lblId.ClientIDMode = System.Web.UI.ClientIDMode.Static;
            lblId.Text = ds.Tables[0].Rows[i]["Id"].ToString();
            td1.Controls.Add(lblId);

            TableCell td2 = new TableCell();
            Label lblTitle = new Label();
            lblTitle.Attributes["style"] = "text-transform:uppercase;";
            //lblTitle.ID = "lbl_" + ds.Tables[0].Rows[i]["SName"].ToString();
            lblTitle.ID = "lblName_" + i;
            lblTitle.ClientIDMode = System.Web.UI.ClientIDMode.Static;
            lblTitle.Text = ds.Tables[0].Rows[i]["SName"].ToString();
            td2.Controls.Add(lblTitle);

            TableCell td3 = new TableCell();
            TextBox txtValue = new TextBox();
            //txtValue.ID = "txt_" + ds.Tables[0].Rows[i]["Id"].ToString();
            txtValue.ID = "txtMarks_" + i;
            txtValue.ClientIDMode = System.Web.UI.ClientIDMode.Static;
            td3.Controls.Add(txtValue);
            //studentList.Controls.Add(new LiteralControl("<br />"));
            tr.Cells.Add(td1);
            tr.Cells.Add(td2);
            tr.Cells.Add(td3);
            table.Rows.Add(tr);
        }
        studentList.Controls.Add(table);
    }

    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        qry = "select * from Student_info where class='" + ddlClass.SelectedValue.ToString() + "' AND section='" + ddlSection.SelectedValue.ToString() + "'";
        SqlCommand cmd = new SqlCommand();
        cmd.Connection = con;
        cmd.CommandText = qry;
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);

        qry = "insert into result (studentname,studentid," + ddlSubject.SelectedItem.ToString() + ") values(@studentname,@studentid,@marks)";
        cmd.CommandText = qry;
        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
        {
            Label lblId = (Label)studentList.FindControl("lblId_" + i);
            Label lblName = (Label)studentList.FindControl("lblName_" + i);
            TextBox txtStudMarks = (TextBox)studentList.FindControl("txtMarks_" + i);

            cmd.Parameters.AddWithValue("@studentname", lblName.Text.ToString());
            cmd.Parameters.AddWithValue("@studentid", lblId.Text.ToString());
            cmd.Parameters.AddWithValue("@marks", Convert.ToInt32(txtStudMarks.Text));
            cmd.ExecuteNonQuery();
        }
        con.Close();
        lblmsg.Text = lblmsg.Text + "Success";
    }