Displaying eventinfo values?

It's easy to obtain the values for the properties and fields or invoke methods but it has been difficult for me to get the delegate from an EventInfo.

I have tried following the instructions from this website:

http://bobpowell.net/eventsubscribers.aspx

and I have tried this code so far:

namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

        }
        private void button1_Click(object sender, EventArgs e)
        {
            System.Reflection.EventInfo[] eventInfo = button1.GetType().GetEvents();

            for (int i = 0; i < eventInfo.Length; ++i) 
            {
                Type senderType = typeof(Form1);
                FieldInfo fi = senderType.GetField(eventInfo[i].Name, BindingFlags.NonPublic | BindingFlags.Instance); 
                if (!Object.ReferenceEquals(null, fi)) 
                {
                    textBox2.Text = fi.GetValue(null) + "\n" + textBox2.Text; 
                    continue; 
                }
                PropertyInfo pi = senderType.GetProperty(eventInfo[i].Name, BindingFlags.NonPublic | BindingFlags.Instance); 
                if (!Object.ReferenceEquals(null, pi)) 
                {
                    textBox2.Text = pi.GetValue(button1, null) + "\n" + textBox2.Text; 
                    continue; 
                }
                EventHandlerList ehl = senderType.GetProperty("Events", BindingFlags.Instance | BindingFlags.Public | BindingFlags.Static | BindingFlags.NonPublic).GetValue(button1, null) as EventHandlerList;
                Delegate del = ehl[fi.GetValue(sender)];
                Delegate[] dels = del.GetInvocationList();
                foreach (Delegate nextDel in del.GetInvocationList())
                {
                    textBox2.Text = nextDel.Method.Name + "\n" + textBox2.Text;
                }
            } 
        }
    }
}

But I get the error "object reference not set to an instance of an object" for this part of the code

Delegate del = ehl[fi.GetValue(sender)];