Technically speaking you should remove your business logic away from your UI layer and have some sort of Validation Object to validate the data in your presentation layer and then post back the results to your view.
Yeah, I agree with that if it is for validation only.
On the other hand, the Cell Value Changed event seems to trigger only when the value of the cell changes, which means the validation code runs only when the value changes and not everytime a user changes cells.
Cell Validating Dim header Text As String = _ data Grid View1. Its works but when i change a cell empty, Formatted Value is empty too.column, its value is tested for validity by checking that it is not empty. I understand that the impact in performance should be irrelevant when using simple validation and conditional highlighting rules but I would as much prefer it not to run useless code everytime the user moves to another cell if it can be avoided.Thanks, Depends on what design pattern (if any) you are following.