When the cell is actively editing, it is the cell control that handles the keys and would manage the paste. I am not sure what you are doing to get editable summary cells, but for editable recordfieldcells, handling TableControlCurentCellControlKeyMessage allows you to catch the ctl+V and handle teh paste.
private void gridGroupingControl1_TableControlCurrentCellControlKeyMessage(object sender, Syncfusion.Windows.Forms.Grid.Grouping.GridTableControlCurrentCellControlKeyMessageEventArgs e)
{
Keys keyCode = (Keys) ((int)e.Inner.Msg.WParam) & Keys.KeyCode;
if(e.Inner.Msg.Msg == 0x100 && keyCode == Keys.V && 0 != (Control.ModifierKeys & Keys.Control))
{
GridTextBoxCellRenderer cr = e.TableControl.CurrentCell.Renderer as GridTextBoxCellRenderer;
if(cr != null && cr.TextBox.Text.Length == cr.TextBox.SelectionLength)
{
if(Clipboard.GetDataObject().GetDataPresent(typeof(string)))
{
string s = (string)Clipboard.GetDataObject().GetData(typeof(string));
cr.TextBox.SelectedText = s;
e.Inner.Handled = true;
e.Inner.Result = true;
}
}
}
}