How to Run 2 functions on asp.net button onclick

Question

I want to run 2 functions which is displayTable() and ExportCSV() on RunKDF_OnClick button, but i only able to run one of the function which is ExportCSV(). Below is my code.

    public void RunKDF_OnClick(object sender, EventArgs e)
    {

        ConnectionInfo connectionInfo = new ConnectionInfo("xx.xx.xx.xxx", xx, "root", new 
        AuthenticationMethod[]
        {
            // Pasword based Authentication
            new PasswordAuthenticationMethod("root","xxxx"),
        });

        using (SshClient ssh = new SshClient(connectionInfo))
        {
            ssh.Connect();
            ssh.RunCommand("perl -w /tmp/ThermalValue/bin/kdf2csv/thermalKDF.pl");
            ssh.RunCommand("exit");

            ssh.Disconnect();
        }

        displayTable();
        ExportCSV();
    }

    public void displayTable()
    {
        string connectionString = @"Data Source = xxxxx; port = xxxx; Initial Catalog = xxxx; User Id = xxxxx; password = xxxxx";
        using (MySqlConnection sqlCon = new MySqlConnection(connectionString))
        {
             sqlCon.Open();
             MySqlDataAdapter sqlDa = new MySqlDataAdapter("SELECT UID AS UNIT_ID ,Tvalue AS Temperature_Value , File AS KDF_File_Name FROM OEE_PROD.thermal", sqlCon);
             DataTable table = new DataTable();
             sqlDa.Fill(table);
             GridView1.DataSource = table;
             GridView1.DataBind();   
        }
    }

//This is ExportCSV method.

public void ExportCSV() { string conn = @"Data Source = xxxxx; port = xxxx; Initial Catalog = OEE_PROD; User Id = xxxx; password = xxxxx"; using (MySqlConnection con = new MySqlConnection(conn)) {

 using (MySqlCommand cmd = new MySqlCommand("SELECT UID AS UNIT_ID, Tvalue AS Temperature_Value, File AS KDF_File_Name FROM OEE_PROD.thermal"))
 {
  using (MySqlDataAdapter sda = new MySqlDataAdapter())
   {
     cmd.Connection = con;
     da.SelectCommand = cmd;
     using (DataTable dt = new DataTable())
      {
         sda.Fill(dt);

         //Build the CSV file data as a Comma separated string.
           string csv = string.Empty;

            foreach (DataColumn column in dt.Columns)
             {
              //Add the Header row for CSV file.
               csv += column.ColumnName + ',';
              }

              //Add new line.
              csv += "\r\n";

              foreach (DataRow row in dt.Rows)
              {
               foreach (DataColumn column in dt.Columns)
                 {
               //Add the Data rows.
              csv += row[column.ColumnName].ToString().Replace(",", ";") + ',';
                            }

                //Add new line.
               csv += "\r\n";
                 }

                //Download the CSV file.
               Response.Clear();
               Response.Buffer = true;
               Response.AddHeader("content-disposition", "attachment;filename=KDFExport_"+DateTime.Now+".csv");
               Response.Charset = "";
               Response.ContentType = "application/text";
               Response.Output.Write(csv);
               Response.Flush();
               Response.End();


              }
           } 

       }
   }

//This is my aspx for gridview

<asp:GridView CssClass="GridView" Width="100%" ID="GridView1" runat="server" CellPadding="4" ForeColor="#333333" GridLines="None">
            <Columns>
                    <asp:TemplateField HeaderText="No">
                        <ItemTemplate>
                            <%# Container.DataItemIndex + 1 %>
                        </ItemTemplate>
                        </asp:TemplateField>
              </Columns>
             <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
             <EditRowStyle BackColor="#999999" />
             <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
             <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
             <PagerSettings FirstPageText="First" LastPageText="Last" />
             <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
             <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
             <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
             <SortedAscendingCellStyle BackColor="#E9E7E2" />
             <SortedAscendingHeaderStyle BackColor="#506C8C" />
             <SortedDescendingCellStyle BackColor="#FFFDF8" />
             <SortedDescendingHeaderStyle BackColor="#6F8DAE" />

          </asp:GridView>

Answer 1

The problem is that you are calling Response.End to early. https://learn.microsoft.com/en-us/dotnet/api/system.web.httpresponse.end?view=netframework-4.8

ends all currently buffered output to the client, stops execution of the page, and raises the EndRequest event