To reproduce: void grid_RowValidating(object sender, RowValidatingEventArgs e) { e.Cancel = true; } Pressing the escape key should cancel the edit mode and revert the value
Pressing the Escape key will cancel the edit mode and will revert the value of the date time cell when the cell is in edit mode. This is the default behavior for the cells. Still, this can be done before the value is committed to the cell i.e. when the editor is not closed and by this time the RowValidating it not yet fired.
This should work for all column types.