How to display all the numbers of my random c# form

I want to generate 500 random number between 1 to 200 and display all this number, but i have just one on the screen.

        private void cmdGenererNombres_Click(object sender, EventArgs e)
    {
        Random rand = new Random(500);
        int number = rand.Next(1, 201);

        FileStream fs = new FileStream("Binaire.bin", FileMode.Create, FileAccess.Write, FileShare.None);
        BinaryWriter bw = new BinaryWriter(fs);
        bw.Write(number);

        bw.Close();
        fs.Close();
    }

    private void cmdAfficherNombres_Click(object sender, EventArgs e)
    {
        FileStream fsSource = new FileStream("Binaire.bin", FileMode.Open, FileAccess.Read, FileShare.None);
        BinaryReader br = new BinaryReader(fsSource);

        MessageBox.Show(br.ReadByte().ToString());

        br.Close();
        fsSource.Close();
    }

>Solution :

You could use a combination of Chunk and string.join to combine all the numbers into a single, large string.

var rand = new Random(42);
var rows = Enumerable.Range(0, 500)
    .Select(i => rand.Next(0, 201))
    .Chunk(50) // number of values per row
    .Select(r => string.Join(", ", r.ToString("000")); // Combine the values in each row. Use fixed width formatting

var block = string.Join(Environment.NewLine, rows); // combine rows into a block

MessageBox.Show(block);

Formatting the numbers as a block should help in keeping the text within the width and height of the screen.

An alternative would be to create your own UI with a scrollable textbox or something similar to show all the numbers.