how to convert _list(QuerySnapshot<Map<String, dynamic>> snapshot) into List<dynamic> in flutter 2.0

Issue

I’m trying to get a List<dynamic’> _list but since I upgraded flutter to 2.0, I had to change my code to _list(QuerySnapshot<Map<String, dynamic>> snapshot). that type don’t have length, or elementAt like normal List<dynamic’> type. it is possible to convert it?

my code:

List _list(QuerySnapshot<Map<String, dynamic>> snapshot) {
                              return snapshot.docs
                                  .map((doc) => new Brand(
                                        doc.data()['brandId'].toString(),
                                      ))
                                  .toList();
                            }

later on my code I need use some fields:

return StaggeredGridView.countBuilder(
                              itemCount: _list.length,
                              itemBuilder: (BuildContext context, int index) {
                                Brand brand = _list.elementAt(index) as Brand;
                                return InkWell(
                                  onTap: () {
                                    Navigator.of(context).pushNamed('/Brand',
                                        arguments: new RouteArgument(
                                            id: _list[index].id)

the error message:
error: The operator ‘[]’ isn’t defined for the type ‘List Function(QuerySnapshot<Map<String, dynamic>>)’

any ideas are welcome, thank’s in advance!

Solution

as of now your _list is defined as a Function that returns a List rather than being a List itself.

So, in order to use it, you should firstly properly call it with the necessary parameter.

Like this,

List myList = _list(snapshot);  // I assume you have access to a snapshot variable
return StaggeredGridView.countBuilder(
  itemCount: myList .length,
  itemBuilder: (BuildContext context, int index) {
  Brand brand = myList.elementAt(index) as Brand;
  return InkWell(
    onTap: () {
      Navigator.of(context).pushNamed('/Brand',
        arguments: new RouteArgument(
        id: myList[index].id
      )
  ..... 

Answered By – Nisanth Reddy

Answer Checked By – Senaida (FlutterFixes Volunteer)