DfBAdminToolkit.View.DevicesView.ObjectListView_DeviceList_HeaderCheckBoxChanging C# (CSharp) Method

        private void ObjectListView_DeviceList_HeaderCheckBoxChanging(object sender, HeaderCheckBoxChangingEventArgs e)
        {
            ObjectListView olv = sender as ObjectListView;
            CheckState newState = e.NewCheckState;
            if (newState == CheckState.Checked)
            {
                // suppress message box
                _suppressErrorMessage = true;
                if (olv.Objects != null)
                {
                    olv.CheckAll();
                }
                _suppressErrorMessage = false;
            }
            else if (newState == CheckState.Unchecked)
            {
                if (olv.Objects != null && olv.CheckedObjects.Count > 0)
                {
                    olv.UncheckAll();
                }
            }
        }