C＃中的随机数

Question

i use

Random rnd = new Random();
x=rnd.Next(10);

but every time i get the same number. how to fix it and get different numbers? Tell me easy method.

thanks. sorry for bad english.

Answer 1

Random's default constructor uses the current time as its seed. Therefore, if you initialize multiple Random objects in rapid succession (such as in a loop, for instance), they will share the same seed.

Create your Random object once and use it multiple time, or create a seed beforehand and use it to initialize your generators.

Answer 2

MSDN explicitly addresses this "problem" in the remarks section of the MSDN docs for the Random class, including a sample!

http://msdn.microsoft.com/en-us/library/system.random.aspx

Answer 3

Obligatory XKCD reference:

http://xkcd.com/221/

Answer 4

Make sure you use the constructor only once. You can add a seed.

Random rnd  = new Random(DateTime.Now.Millisecond);

Then you can make calls to as you actually did it.

x=rnd.Next(10);

But make sure you don't have the constructor and the call to the Next() method inside a loop or something similar...