I am trying to add the contents of a text file to a text box in a child form using 'Open' from the parent file. This is what I have so far:
 
private void openToolStripMenuItem_Click(object sender, EventArgs e)
         {
             openFileDialog1.InitialDirectory = Directory.GetCurrentDirectory();
            
             // Display the file open dialog box and show only text files.
             DialogResult responseDialogResult;
             openFileDialog1.Filter = "Text Files (*.txt)|*.txt";
             responseDialogResult = openFileDialog1.ShowDialog();
             
             // Check that the user did not click the cancel button.
             if (responseDialogResult != DialogResult.Cancel)
             {
                 // Open the child form. 
                 Form2 childOneForm = new Form2();
                 childOneForm.MdiParent = this;
                 childOneCountInteger++;
                 childOneForm.Text = openFileDialog1.FileName;
                 childOneForm.Show();