Answers for "listview horizontal separator"

listview.separated flutter

ListView.separated(
  itemCount: 25,
  separatorBuilder: (BuildContext context, int index) => Divider(),
  itemBuilder: (BuildContext context, int index) {
    return ListTile(
      title: Text('item $index'),
    );
  },
)

linearlayout horizontal in recyclerview

mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, true));

flutter reorderable list view dividers

//in children property of ReorderableListView
children: [
        for(final item in menu.dishCategories)
          Column(
            key: ValueKey(item),
            //set mainAxisSize to min to avoid items disappearing on reorder
            mainAxisSize: MainAxisSize.min,
            children: [
              ExpansionTile(
                leading: Icon(Icons.menu),
                title: Text(item, style: regularTextStyle),
                children: [

                ],
              ),
              Divider(height: 0)
            ],
          )
      ],