Unique Random Numbers C#

Question

I have a program to generate random lottery numbers in WPF but I don't know how to get unique random numbers. I got this exercise after I studied about the 'if structure' so I guess I should use that somehow but I have no idea how.

Here is my code:

private void btnGo_Click(object sender, RoutedEventArgs e)
{

   Random rd = new Random();

    int marginLeft = 50 + (caPaper.Children.Count * 50);

    Ellipse newBall = new Ellipse();
    newBall.Fill = new SolidColorBrush(Colors.Red);
    newBall.Height = 70;
    newBall.Width = 70;
    newBall.Margin = new Thickness(marginLeft, 100, 0, 0);
    caPaper.Children.Add(newBall);

    TextBlock txt1 = new TextBlock();
    txt1.FontSize = 20;
    txt1.Foreground = Brushes.White;
    txt1.Text = " " + rd.Next(1, 45);
    Canvas.SetTop(txt1, 120);
    Canvas.SetLeft(txt1, marginLeft + 20);
    caPaper.Children.Add(txt1);
}
private void btnClear_Click(object sender, RoutedEventArgs e)
{
    caPaper.Children.Clear();
}

Are you looking for a method to get X random numbers? – fasaas Oct 13 '18 at 15:29 — fasaas, Oct 13 '18 at 15:29
What problem do you have with the above code? – Steve Oct 13 '18 at 15:30 — Steve, Oct 13 '18 at 15:30
That sometimes it generates the same number. – amur567 Oct 13 '18 at 15:35 — amur567, Oct 13 '18 at 15:35

score 1 · Answer 1 · answered Oct 13 '18 at 15:48

1

The easiest way to generate lottery style random numers is

Create a list of all the possible values
Shuffle the list using a robust algorithm (e.g. Fisher Yates)
Take the required number of items from the front of the list

answered Oct 13 '18 at 15:48

Peregrine

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Unique Random Numbers C#

1 Answers1