ขออนุญาติสอบถามเรื่องการ Pass parameter in EventHandler [C#] มีวิธีส่งแบบไหนครับ?

using System;
using System.Windows.Forms;

namespace ExampleEventHandler {
    public partial class EventTutorial : Form {

        public event EventHandler openCustomDialog;

        public EventTutorial() {
            InitializeComponent();
        }

        private void EventTutorial_Load(object sender, EventArgs e) {

            openCustomDialog += EventTutorial_openCustomDialog;
        }

        private void EventTutorial_openCustomDialog(object sender, EventArgs e) {
            MessageBox.Show("Hello Event! : " + sender, "Message");
        }

        private void mbtnSendEvent_Click(object sender, EventArgs e) {
            EventHandler handler = openCustomDialog;
            Button btnParameter = sender as Button;
            if (btnParameter != null) {
                btnParameter.Text = "I was clicked! ^^'";
            }

            if (handler != null) handler(btnParameter.Text, e);
        }
    }

}

Public Class Calculator : Inherits Form

    Private Delegate Function DelegateFormula(ByVal m As Double, ByVal n As Double) As Double
    Private Formula As New Dictionary(Of String, DelegateFormula)() From {{"+", Function(m, n) m + n},
                                                                          {"-", Function(m, n) m - n},
                                                                          {"*", Function(m, n) m * n},
                                                                          {"/", Function(m, n) m / n}
                                                                         }
    'Make Love Click
    Private Sub WhenMakeLove(sender As Object, e As EventArgs) Handles btnPlus.Click, btnSubstract.Click, btnMultiply.Click, btnDivision.Click
        Dim op As String = DirectCast(sender, Button).Tag
        Dim dict = Formula.ElementAt((New Random).Next(0, Formula.Count - 1)) ' Rnd() As Single
        txtResult.Text = "N/A"
        If (("+-*/").Contains(op)) AndAlso (IsNumeric(txtA.Text) AndAlso IsNumeric(txtB.Text)) AndAlso (Not (op = "/" AndAlso CDbl(txtB.Text) = 0)) Then
            txtResult.Text = Formula(op).Invoke(txtA.Text, txtB.Text)
        End If

    End Sub
End Class