NET random random number duplication problem

In the actual project not only need to randomly generate the password string, but also to generate more than one at a time. I put the method of generating the random string into the for loop, and the problem arises.

The resulting string is duplicated.

After multiparty verification, the reason in the code.

// use seed associated with the system time New Random ();

The problem is that the system time is updated at 10ms, and the For loop is much shorter than 10ms, so there will be duplicates.

How to fix it, of course, is not using the default seed, manually specified, and the seed cannot be duplicated . I think the counter in the For loop is right.

 for (int0; i < count; i++) {     // Take I as seed, generate random number     new  Random (i);}

Perfect solution.