i am using https://github.com/woxblom/DragListView lib i want to group data although i have set pragmatically margins on base of id data grouping fine but when i scroll vertically up and down group mixed up so i used another technique i set adapter which is extended of recyclerview.Adapter and i used its own viewHolder and inside its adapter used same techniques that in lib and in this way data grouped but i stuck for dragging and dropping when i drop item in other column it show error
java.lang.NullPointerException: Attempt to invoke virtual method 'void presentation.khanban.dragList.DragItemAdapter.setDragItemId(long)' on a null object reference
i know dragItemId adapter is null but i dont know how to set it.as i attached screenShot any help appreciated thanks
