protected void btnRefresh_Click(object sender, EventArgs e)
{
gvwBilling.DataSource = BillingService.GetBillingData(
Convert.ToInt32(ddlBranch.SelectedValue),
Convert.ToInt32(ddlBillingType.SelectedValue),
cblCustomerStatus.Items.Cast <ListItem>().Where(item => item.Selected).Select(item => Convert.ToInt32(item.Value)).ToArray(),
cblMembershipType.Items.Cast <ListItem>().Where(item => item.Selected).Select(item => Convert.ToInt32(item.Value)).ToArray(),
calFindDateFrom.SelectedDate.GetValueOrDefault(DateTime.Today),
calFindDateTo.SelectedDate.GetValueOrDefault(DateTime.Today)).OrderBy(data => data.CustomerBarcode);
gvwBilling.DataBind();
foreach (GridViewRow gridRow in gvwBilling.Rows)
{
(gridRow.Cells[gridRow.Cells.Count - 1].Controls[1] as CheckBox).Checked = true;
}
}