Why doesn't my GridView show up?

Question

EDIT: I forgot to bind the datatable (oops), that is now fixed. The program now crashes, and I am still confused as too why.

I am making a website where I want to display a data table that has had its rows and columns switch. I wrote some c# to do this. My code compiles and runs without crashing, but the gridview where I put this data never shows up. If I remove the code binding the data to the gridview, and instead use a sql source connection, it shows (but obviously is not flipped).

Why is my gridview not showing up and how would I go about fixing it?

C#:

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

namespace MachineUpdateFrontEnd
{
    public partial class NewUpdate : System.Web.UI.Page
    {
        DataSet input;
        DataSet output;

        protected void Page_Load(object sender, EventArgs e)
        {
            DataSet temp = pullData(UpdateSqlDataSource.ConnectionString);
            input = SwitchRows(temp);
            GridView1.DataSource = input.Tables[0];
        }

        private DataSet pullData(string ConStr) {
            DataSet ds = new DataSet();
            SqlDataAdapter adp = new SqlDataAdapter("select * from MachineUpdate", ConStr);
            adp.Fill(ds, "MachineUpdate");
            return ds;
        }

        private void pushData() {
            output = SwitchRows(input);
        }

        private DataSet SwitchRows(DataSet input)
        {
            DataSet ds = new DataSet();

            foreach (DataTable dt in input.Tables) {
                DataTable inputTable = new DataTable();
                for (int i = 0; i < dt.Rows.Count; i++) {
                    inputTable.Columns.Add(Convert.ToString(i));
                }
                DataRow r;
                for (int j = 0; j < dt.Columns.Count; j++) {
                    r = inputTable.NewRow();
                    r[0] = dt.Columns[j].ToString();
                    for (int k = 1; k < dt.Rows.Count; k++) {
                        r[k] = dt.Rows[k - 1][j];
                    }
                    inputTable.Rows.Add(r);
                }
                ds.Tables.Add(inputTable);
            }
            return ds;
        }
    }
}

ASP:

<%@ Page Title="" Language="C#" MasterPageFile="~/Master.Master" AutoEventWireup="true" CodeBehind="NewUpdate.aspx.cs" Inherits="MachineUpdateFrontEnd.NewUpdate" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="body" runat="server">
    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="True" DataKeyNames="UpdateID" style="margin-top: 0px" ShowHeaderWhenEmpty ="true">
        <Columns>
            <asp:BoundField DataField="UpdateID" HeaderText="UpdateID" InsertVisible="False" ReadOnly="True" SortExpression="UpdateID" />
            <asp:BoundField DataField="MachineID" HeaderText="MachineID" SortExpression="MachineID" />
        </Columns>
    </asp:GridView>
    <asp:SqlDataSource ID ="UpdateSqlDataSource" runat ="server" ConnectionString="<%$ ConnectionStrings:MachineUpdateDataBaseConnectionString %>" SelectCommand="SELECT * FROM [MachineUpdate MQ]">

    </asp:SqlDataSource>
</asp:Content>

Entire project:

https://github.com/Darokrithia/MachineUpdateFrontEnd

Answer 1

I don't see you are binding the gridview with the datasource like

GridView1.DataSource = input.Tables[0];
GridView1.DataBind();   //missing data binding