Cellvalidating event order
The Data Bound Item will be updated only if the cell is validated.
In this case, you need to add a Combo Box to the cells in the desired column. This scenario can be achieved by using the Row Validating event, which is fired when the user tries to change the current row (changing to another row or when the control loses focus).Note that only the Cell Validating event can keep the editor active,when the validation fails and it does not allow the user to exit the cell until a valid value is filled.At this moment, a Cell Validating event is fired and since the new value is not committed yet to the underlying data object, here is the perfect place for applying a custom UI validation. The Row Validating event is very similar to the Cell Validating event. Once you have added such errors, you will have to explicitly clear them when needed.Example 3 shows how to validate the Order No property of the Order object to be longer than 5 characters. However, instead of getting an individual cell, you are getting an entire row. Please check this help article for information about how to clear user defined errors. Example 7 shows you how to use Data Annotations in order to validate the Order NO property of the Order object.