Pass extended class of an abstract class as a parameter in flutter-CodePudding

I am trying to build a website using flutter but I can't figure out. This is an abstract class.

abstract class TableBaseClass {
  int getPage(BuildContext context);
  void setPage(int val,BuildContext context);
  int getPagination();
  void setPagination(String val,BuildContext context);
  void setSearch(String val,BuildContext context);
  String getSearch();
  dynamic getData();
  List getHeaders();
  List getBodyFields();
  void refresh(BuildContext context);
  void setSort(String header);
  void setOrder(String order,BuildContext context);
  String getOrder();
}

And this class is extending it.

class Objects extends TableBaseClass with ChangeNotifier {

and this widget takes the abstract class as a parameter.

class TableWidget extends StatefulWidget {
  final TableBaseClass provider;
  final String menuButton;

  const TableWidget(this.provider,this.menuButton, {super.key});

but when I pass the Objects class TableWidget(Objects,menuButton) It gives error The argument type 'Type' can't be assigned to the parameter type 'TableBaseClass'.

Any help is appreciated in advance.

CodePudding user response：

because you're simply trying to pass a Type, not an instance of the TableBaseClass class, you didn't call the class constructor, see this:

print(TableBaseClass); // this is a type, 
print(TableBaseClass.runtimeType); // Type

but with (), you're creating an instance of that class:

print(TableBaseClass()); // this is an instance of TableBaseClass 
print(TableBaseClass().runtimeType); // TableBaseClass