Hi Peter,
Thank you for using Syncfusion products.
You cannot add new items directly to the ArrayList through the grid. But you can add new items to ArrayList by implementing IBindingList interface since AddNew method is available only in that interface. Implementation of IBindingList.AddNew as well as the IBindingList.AllowNew property will let you to add new rows.
Please refer to the simple sample available in the below link that illustrates the same:
http://websamples.syncfusion.com//samples/ Grid.Windows//F70854/main.htmFor more details, you can refer our online documentation or the local documentation available in the dashboard under the category:
Essential Grid---->Grid Control---->Basic concepts ---->GridDataBoundGrid Use Cases---->Binding to an ArrayList---->ArrayList Class with IBindingList Support
Kindly let me know if you have any questions.
Regards,
Subhasheela R