Datareader counter for showing progress/cancel reading the data

hi,
I want to show in a seperate form the numbers (counter) of records read from a datareader.
I need this to show the progress and the option to cancel/stop the datareader from reading.
I don't know how to do it to get it works....RecordCounterForm is still empty :-(
// Mainform
..
..
RecordCounterForm rc = new RecordCounterForm();
int RecordCount = 0;
rc.ChildText = "Start met tellen";
rc.Show();
while (reader.Read())
{                                       
  RecordCount++;
  rc.ChildText = RecordCount.ToString();
  // if  rc.CancelButton then stop
}
..
..
///childform with the counter
namespace Demo
{
    public partial class RecordCounterForm : Form
    {
         public RecordCounterForm()
        {
            InitializeComponent();
        }
        public String ChildText
        {
            get { return txtChildText.Text; }
            set { txtChildText.Text = value; }
        }
        private void btnCancel_Click(object sender, EventArgs e)
        {
             this.Close();
        }
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
          
            this.Close();
        }

        private void UpdateText(string ChildText)
        {
            txtChildText.Text = ChildText;
           
        }
    }
}