checkbox - How to randomly fill checkboxes in c# - Visual Studio

So this is my first question on . I'm working on a drum sequencer
and want to implement a button to randomly fill the 80 checkboxes that indicate a drum
sound being triggered. Currently what I have only filles one box of the 80 randomly, but
I want each of them to have a random chance of being filled. The first part of my code
simply clears the current selection. Here is my attempt in the following
code:

private void
            button4_Click(object sender, EventArgs e)

{

            List Checkboxlist = new List();
 foreach
            (CheckBox control in this.Controls.OfType())
 {

            Checkboxlist.Add(control);
 control.Checked = false;

            }

 for (int i = 0; i <= 200; i++)

            {

 var random = new Random();
 var r = random.Next(0,
            Checkboxlist.Count);
 var checkbox = Checkboxlist[r];

            checkbox.Checked = true;

            }
}

Thank
you for looking!

itemprop="text">

class="normal">Answer

Don't create new
Random() inside the loop. It is better to declare the random once, the best
way is to create it as static
member.

private static Random
            random = new Random(); // Class member

private void
            button4_Click(object sender, EventArgs e)
{
 List
            Checkboxlist = new List();
 foreach (CheckBox control in
            this.Controls.OfType())
 {

            Checkboxlist.Add(control);

 control.Checked = false;

            }

 for (int i = 0; i <= 200; i++)
 {
 var r
            = random.Next(0, Checkboxlist.Count);
 var checkbox =
            Checkboxlist[r];
 checkbox.Checked = true;

            }
}

The
reason for that is:

The random number generation starts from a seed value. If the same seed is used
repeatedly, the same series of numbers is generated. One way to produce different
sequences is to make the seed value time-dependent, thereby producing a different series
with each new instance of Random. By default, the parameterless constructor of the
Random class uses the system clock to generate its seed value,

href="http://msdn.microsoft.com/en-us/library/system.random.aspx"
rel="nofollow">Source

The
rapid for-loop cause the Random to be created with the same seed, so the
Next function returned the same first value of the series of
numbers.