Mouse input in C# windows forms application

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C#

WinForms

PDF

VS2017

Hello Fellow Programmers,

I have made a C# Windows Forms Application in Visual Studio 2017 which opens up any PDF file. The form I use when I run the App is a box with a button (to open the pdf), two textboxes which give the X and Y coordinates of a mouse, and a box where the PDF opens. Unfortunately whenever I click in the PDF box nothing happens. How do I interact with the pdf and show the user where the mouse is during a click?

Code to open PDF:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e) //button to open PDF
        {
            OpenFileDialog openFileDialogE = new OpenFileDialog();

            if (openFileDialogE.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                axAcroPDF1.src = openFileDialogE.FileName;
            }
        }

        private void axAcroPDF1_MouseClick(object sender, MouseEventArgs e)
// supposed to record position on click        
{
            base.OnMouseClick(e);
            textBox1.Text = e.X.ToString();
            textBox2.Text = e.Y.ToString();
        }

        private void axAcroPDF1_MouseUp(object sender, MouseEventArgs e)
        // supposed to record position on release
        {
            textBox1.Text = e.X.ToString();
            textBox2.Text = e.Y.ToString();
            Console.WriteLine("mouse up");
        }
    }
}

What I have tried:

I adjusted an existing code which gives the user the coordinates of clicks wherever they click in a picture box. I modified it so that it would maybe work with a PDF box. I used it in my C# code. I also tested out the existing program by itself and it didn't work either.
I eventually want to output the on screen distance between when I start a click and when I let go.

Original code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

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

        protected void pictureBox1_MouseClick(MouseEventArgs e)
        {
            base.OnMouseClick(e);
            textBox1.Text = e.X.ToString();
            textBox2.Text = e.Y.ToString();
        }

       private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            textBox1.Text = e.X.ToString();
            textBox2.Text = e.Y.ToString();
            Console.WriteLine("mouse up");
        }
    }
}