Hello Vasily,

Internal to the XamGrid, if filtering or an AddNewRow is enabled, we use reflection to attempt to create an empty object of the type that corresponds to a particular ColumnLayout in the grid. For filtering, this is used as a sort of placeholder to filter against. For the AddNewRow, this is used as a placeholder "template" for an underlying data item to correspond to the new records that will be added to the grid, and as such, the underlying collection. It appears to me that much of this is likely done for performance reasons, as we wouldn't want to get the underlying type of the data items to the rows for each row filtered or added each time we go to do this operation and so the placeholder is used to prevent this unnecessary overhead.

If there is no default, parameter-less constructor for the elements to be created via reflection, we require that you create one and return it in the DataObjectRequested event. We cannot assume that we need to pass N number of parameters to the element we create, as this number could be any number of parameters. As such, I would recommend that you either return an "empty" object from the DataObjectRequested event as shown in the forum thread linked above, or add an empty, parameter-less constructor to your underlying data item, if possible.

Please let me know if you have any other questions or concerns on this matter.

Sincerely,
Andrew
Associate Developer

Yes, I allow filtering, but I still don't understand why this object needed. Also, I use filtering as Filter menu and I don't see the similar approach with AddNewRow functionality. What does this object do in the internal logic of the XamGrid?