Datagridview cellvalidating not working
If you are still experiencing any further difficulties, it would be greatly appreciated if you specify in details what is the exact goal that you are trying to achieve.
Cancel Edit() it causes the Cell Validated event to fire when it shouldn't. GIF screen recording describing this behavior with your example project: https://1drv.ms/i/s!
"The validating event is firing because focus is being moved from the DGV to the button.
column, its value is tested for validity by checking that it is not empty.