The relationship between the construction method, the time seed and the sequence of random numbers in the "C #" Random class

The Random class constructor

1) random random = new random (); //Parameterless constructor uses the system clock to generate its seed value

However, the range of system clock values is limited , so in small-scale calculations, it may not be possible to call this constructor with different seed values, which will result in two random objects generating the same number sequence.

1 usingSystem;2 usingSystem.Collections.Generic;3 4 namespacefirsttest5 {6     class Program7     {8         Static voidMain (string[] args)9         {TenRandom random1 =NewRandom (); Onelist<int> List1 =Newlist<int>(); A getrandomnumbers (random1, list1); -Console.WriteLine ("the Random1 object uses the default constructor to generate a sequence of random numbers:"); - printlist (list1); the  -Random random2 =NewRandom (); -list<int> List2 =Newlist<int>(); - getrandomnumbers (Random2, list2); +Console.WriteLine ("the Random2 object uses the default constructor to generate a sequence of random numbers:"); - printlist (list2); +         } A  at         Private Static voidGetrandomnumbers (Random rand, list<int>list) -         { -              for(inti =1; I <= the; i++) -             { -List. ADD (Rand. Next (0, -)); -             } in         } -  to         Private Static voidPrintlist (list<int>list) +         { -             foreach(intElementinchlist) the             { *Console.Write ("{0, 5}", Element); $             }Panax Notoginseng Console.WriteLine (); -         } the     } +}

Operation Result:

2) random random = new Random (Int32); The //parameterized constructor initializes the random class instance with the specified seed value and, if a negative number is specified, uses its absolute value as the time seed.

Create random objects that have a large range of time seed values over time to ensure that when you generate several random objects, there is a difference in the sequence of numbers between each other.

• Typically, the number of ticks (Ticks) is used as the time seed:

1 random random = new random ((int) DateTime.Now.Ticks);

Operation Result:

• Alternatively, the time seed is generated by the cryptographic random number generator (RNG):

1Random random =NewRandom (Getrandomseed ());2 3 Static intgetrandomseed ()4 {5     byte[] bytes =New byte[4];6System.Security.Cryptography.RNGCryptoServiceProvider rng =NewSystem.Security.Cryptography.RNGCryptoServiceProvider ();7 rng. GetBytes (bytes);8     returnBitconverter.toint32 (Bytes,0);9}

Operation Result:

The relationship between the construction method, the time seed and the sequence of random numbers in the "C #" Random class