How to randomize seed in C# [duplicate]

问题:

This question already has answers here:

How do I generate a random int number? (32 answers)

Closed 3 years ago.

I need to generate random int in C#. I am using clock time to set the seend. However, as the rnd.Next() function may take less than a millisecond, this does not work if one has to generate a list of ints.

        for( int i=0; i<5; i++) {
            int max_val = 10; // max value
            var rnd = new Random(DateTime.Now.Millisecond);
            int randind = rnd.Next(0, max_val);
            Console.WriteLine(randind);
        }

Output:
1 5 5 5 5

How can one randomise the seed in a clean way without adding an ugly sleep?

回答1:

Create your Randomobject outside the loop and don't provide the seed parameter -- one will be picked for you. By taking it out of the loop, rnd.Next() will give you a random sequence anyway.

   var rnd = new Random();     
   for( int i=0; i<5; i++) {
        int max_val = 10; // max value
        int randind = rnd.Next(0, max_val);
        Console.WriteLine(randind);
    }

回答2:

The Guid Object guaranties a different result each time. You could do this:

... new Random(Guid.NewGuid().GetHashCode())