Index was out of range

See more:

C#3.5

My code as follows

private void SaveCheckedValues()
        {
            System.Collections.ArrayList userdetails = new System.Collections.ArrayList();
            int index = -1;
            foreach (GridViewRow gvrow in grdRpt.Rows)
            {
                object o = grdRpt.DataKeys[gvrow.RowIndex].Value;
                index = (int)0;
                bool result = ((CheckBox)gvrow.FindControl("chkselecdata")).Checked;

                // Check in the Session
                if (Session["CHECKED_ITEMS"] != null)
                    userdetails = (System.Collections.ArrayList)Session["CHECKED_ITEMS"];
                if (result)
                {
                    if (!userdetails.Contains(index))
                        userdetails.Add(index);
                }
                else
                    userdetails.Remove(index);
            }
            if (userdetails != null && userdetails.Count > 0)
                Session["CHECKED_ITEMS"] = userdetails;
        }

when i run the above code shows error as follows

index was out of range.
Must be non-negative and less than the size of the collection parameter name 'Index'

The error show in below line as follows

object o = grdRpt.DataKeys[gvrow.RowIndex].Value;


In the gridview values as follows

transacteeid      totalprice   Qty   Isactive

109453628727        25           1      1
109453628727        15           2      1
565676778            8           3      1

When i debug and check in the value i get value as "109453628727"

how to solve this error. what is the mistake in my above code.

What I have tried:

My code as follows

private void SaveCheckedValues()
{
System.Collections.ArrayList userdetails = new System.Collections.ArrayList();
int index = -1;
foreach (GridViewRow gvrow in grdRpt.Rows)
{
object o = grdRpt.DataKeys[gvrow.RowIndex].Value;
index = (int)0;
bool result = ((CheckBox)gvrow.FindControl("chkselecdata")).Checked;

// Check in the Session
if (Session["CHECKED_ITEMS"] != null)
userdetails = (System.Collections.ArrayList)Session["CHECKED_ITEMS"];
if (result)
{
if (!userdetails.Contains(index))
userdetails.Add(index);
}
else
userdetails.Remove(index);
}
if (userdetails != null && userdetails.Count > 0)
Session["CHECKED_ITEMS"] = userdetails;
}

when i run the above code shows error as follows

index was out of range.
Must be non-negative and less than the size of the collection parameter name 'Index'

The error show in below line as follows

object o = grdRpt.DataKeys[gvrow.RowIndex].Value;


In the gridview values as follows

transacteeid totalprice Qty Isactive

109453628727 25 1 1
109453628727 15 2 1
565676778 8 3 1

When i debug and check in the value i get value as "109453628727"

how to solve this error. what is the mistake in my above code.