"Object Reference is required for non-static field"

Question

So I needed to make a random number generator for my minesweeper project, and I decided to put it in a method.

public static void GenerateBombs(int gsize, int numbombs, HashSet<int> numbers)
    {
        int num = gsize * gsize;
        while (numbers.Count < numbombs)
        {
            numbers.Add(Random.Next(1, num));
        }
    }

However I keep getting the "Object Reference needed for non-static field, property, or method." I don't know why and I can't figure it out from the other questions.

Answer 1

Do like this:

private static Random rand = new Random();

public static void GenerateBombs(int gsize, int numbombs, HashSet<int> numbers)
{
    int num = gsize * gsize;
    while (numbers.Count < numbombs)
    {
        numbers.Add(rand.Next(1, num));
    }
}

Answer 2

The method Next() of the class Random is not a static method. You have to declare an instance of the class Random first:

static Random random = new Random();

then you can use it as numbers.Add(random.Next(1, num)) , now using the static instance of the class instead of the class itself.