Velosity of number generator

If you want to make sure there are no duplicate numbers, you must put each generated number in an array or array list. Every time you click the button you must loop through the generated numbers and compare them to the newly generated number. If there is a duplicate number you must generate another until it is unique.

or please check the following Article:

http://www.c-sharpcorner.com/UploadFile/nanujogi/GenerateUniqueNumberinCSharp12022005233031PM/GenerateUniqueNumberinCSharp.aspx

Hi,

To generate a non duplicate random number, insert all the random number generated in to a hash table with the number as key.Each time when the random number generated check with the HashTable value,if it already exists go for next random  number.

Thanks,

Aru

protected void Page_Load(object sender, EventArgs e)
    {
      int intreturnValue = RandomNumber(100000, 999999);
             
    }

private int RandomNumber(int min, int max)
    {
        Random random = new Random();
        return random.Next(min, max);
    }