How to store an array and make it available after postback - asp.net

Question

I need some help keeping an array after postback.
On page load I am creating a array that contains three random numbers and sorts them from lowest to highest. These numbers are then used to compare characters stored in another string in the positions of the generated numbers.
When the submit button is hit the numbers are regenerated and the verification fails as now there is a new set of numbers.
here is part of the code ... the array i need to keep is rannumInt.
int[] rannumInt = { 0, 0, 0 };
protected void page_load()
{
if (!IsPostBack)
{
int i, j;
if (rannumInt[0] == 0)
{
for (i = 0; i < 3; i++)
{
Random rannum = new Random();
rannumInt[i] = rannum.Next(1, 9);
if (i > 0)
{
for (j = 0; j < i; j++)
{
if (rannumInt[i] == rannumInt[j])
{
i--;
}
}
}
}
Array.Sort(rannumInt);
Label1.Text = Convert.ToString(rannumInt[0]);
TextBox1.Text = Convert.ToString(rannumInt[0]);
Label2.Text = Convert.ToString(rannumInt[1]);
TextBox2.Text = Convert.ToString(rannumInt[1]);
Label3.Text = Convert.ToString(rannumInt[2]);
TextBox3.Text = Convert.ToString(rannumInt[2]);
}
}
else
{
}
}

Answer 1

You will have to store rannumInt somewhere, like a Session or ViewState. Then when a PostBack occurs, convert the ViewState back to an array.
if (!Page.IsPostBack)
{
if (rannumInt[0] == 0)
{
Array.Sort(rannumInt);
Label1.Text = Convert.ToString(rannumInt[0]);
//save the array into the viewstate
ViewState["rannumInt"] = rannumInt;
}
}
else
{
//check if the viewstate exists
if (ViewState["rannumInt"] != null)
{
//convert it back to an int[]
rannumInt = ViewState["rannumInt"] as int[];
}
}
If you want the number to be the same across multiple pages and/or page reloads, use Session