Question

I have 4 numeric up down controls on a form. They are set to hexidecimal, maximum 255, so they’ll each have values from 0 to FF. I’d like to concatenate these values into a string for a textbox.

Answer 1

Assuming you gave the NUDs their default names:

private void button1_Click(object sender, EventArgs e) {
  string txt = "";
  for (int ix = 1; ix <= 4; ++ix) {
    var nud = Controls["numericUpDown" + ix] as NumericUpDown;
    int hex = (int)nud.Value;
    txt += hex.ToString("X2");
  }
  textBox1.Text = txt;
}