Index was out of range. Must be non-negative and less than t

Question

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

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindData();
}
}
protected void BindData()
{
String strConnString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;
SqlConnection con = new SqlConnection(strConnString);
SqlCommand cmd = new SqlCommand("select * from [transact].[transaction_item] where status = 'new'", con);
con.Open();
SqlDataAdapter da = new SqlDataAdapter();
DataSet ds = new DataSet();
da.SelectCommand = cmd;
da.Fill(ds);
grdRpt.DataSource = ds;
grdRpt.DataBind();
}
protected void grdRpt_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
grdRpt.PageIndex = e.NewPageIndex;
BindData();
}
private void PopulateCheckedValues()
{
System.Collections.ArrayList userdetails = (System.Collections.ArrayList)Session["CHECKED_ITEMS"];
if (userdetails != null && userdetails.Count > 0)
{
foreach (GridViewRow gvrow in grdRpt.Rows)
{
int index = (int)grdRpt.DataKeys[gvrow.RowIndex].Value;
if (userdetails.Contains(index))
{
CheckBox myCheckBox = (CheckBox)gvrow.FindControl("chkselecdata");
myCheckBox.Checked = true;
}
}
}
}
private void SaveCheckedValues()
{
System.Collections.ArrayList userdetails = new System.Collections.ArrayList();
int index = -1;
foreach (GridViewRow gvrow in grdRpt.Rows)
{
index = (int)grdRpt.DataKeys[gvrow.RowIndex].Value;
bool result = ((CheckBox)gvrow.FindControl("chkselecdata")).Checked;
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;
}
protected void btnsubmit_Click(object sender, EventArgs e)
{
String strConnString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;
SqlConnection con = new SqlConnection(strConnString);
con.Open();
foreach (GridViewRow row in grdRpt.Rows)
{
int key = (int)grdRpt.DataKeys[row.RowIndex].Value;
CheckBox cb = (CheckBox)row.FindControl("chkselecdata");
SqlCommand cmd = new SqlCommand("UPDATE [transact].[transaction_item] SET Status = 'Ready' Where Id=" + key.ToString(), con);
cmd.ExecuteNonQuery();
}
con.Close();
}

in the first page five records will be displayed and in the second page another five records will be displayed.

 

suppose in the first page i check two rows and in the second page i check another two rows means that selected check box rows to be update in the [transact].[transaction_item] in the table.

 

when i run the 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 shows in below line as follows

 

index = (int)grdRpt.DataKeys[gvrow.RowIndex].Value;

 

how to solve this error. please let me know.