I keep getting an error at Line 48, Column 101 (.push(MaterialPageRoute(builder: (_) => SearchPage(HomeApp, getBooks: getBooks)));), "The argument type 'dynamic Function()' can't be assigned to the parameter type 'HomeApp'". I recently started to learn Flutter/dart and have very little knowledge about these errors.

// ignore_for_file: void_checks

import 'package:http/http.dart' as http;
import 'package:googleapis/books/v1.dart';
import 'dart:async';
import 'dart:convert';

import 'package:flutter/material.dart';

import 'package:book_search_app/widgets/book_card.dart';
import 'package:book_search_app/screens/profile.dart';

class HomeApp extends StatefulWidget {
  const HomeApp({Key? key}) : super(key: key);

  @override
  _HomeAppState createState() => _HomeAppState();
}

class _HomeAppState extends State<HomeApp> {
  getBooks() async {
    var response = await http.get(Uri.parse(
        'https://www.googleapis.com/books/v1/volumes?q={search}:keyes&key={api key}'));
    print(response.body);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: PreferredSize(
          preferredSize: const Size.fromHeight(106),
          child: AppBar(
            automaticallyImplyLeading: false,
            shape: const RoundedRectangleBorder(
                borderRadius:
                    BorderRadius.vertical(bottom: Radius.circular(15))),
            backgroundColor: const Color(0xFFC4C4C4),
            title: const Text(
              'Book Search',
              style: TextStyle(fontSize: 24, color: Colors.black),
            ),
            actions: [
              IconButton(
                onPressed: () {
                  Navigator.of(context)
                      .push(MaterialPageRoute(builder: (_) => SearchPage(HomeApp, getBooks: getBooks)));
                },
                icon: const Icon(Icons.search_rounded),
                iconSize: 40,
                color: Colors.black,
              )
            ],
          ),
        ),
        body: const BookCard(),
        bottomNavigationBar: ClipRRect(
          borderRadius: const BorderRadius.vertical(top: Radius.circular(15)),
          child: BottomNavigationBar(
            type: BottomNavigationBarType.fixed,
            backgroundColor: const Color(0xFFC4C4C4),
            items: const [
              BottomNavigationBarItem(icon: Icon(Icons.home), label: 'Home'),
              BottomNavigationBarItem(
                  icon: Icon(Icons.category), label: 'Categories'),
              BottomNavigationBarItem(
                  icon: Icon(Icons.favorite), label: 'Favourite'),
              BottomNavigationBarItem(
                  icon: Icon(Icons.shopping_cart), label: 'Cart'),
              BottomNavigationBarItem(
                icon: Icon(Icons.account_circle_rounded),
                label: 'Profile',
              ),
            ],
          ),
        ));
  }
}

class SearchPage extends StatelessWidget {
  // ignore: non_constant_identifier_names
  SearchPage(HomeApp, {Key? key, required this.getBooks,})
      : super(key: key);

  final myController = TextEditingController();
  final HomeApp getBooks;

  @override
  void dispose() {
    myController.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
          // The search area here
          title: Container(
        width: double.infinity,
        height: 40,
        decoration: BoxDecoration(
            color: Colors.white, borderRadius: BorderRadius.circular(5)),
        child: Center(
          child: TextField(
            controller: myController,
            decoration: InputDecoration(
                prefixIcon: const Icon(Icons.search),
                suffixIcon: IconButton(
                  icon: const Icon(Icons.search),
                  onPressed: () {
                    getBooks;
                  },
                ),
                hintText: 'Search...',
                border: InputBorder.none),
          ),
        ),
      )),
    );
  }
}

If someone can help and explain this error I would be grateful.

CodePudding user response：

The error is because you have passed the type of getbooks parameter as HomeApp in your SearchPage and your are passing a dynamic function argument in it. To solve this you need to make following change to your code

class SearchPage extends StatelessWidget {
  // ignore: non_constant_identifier_names
  SearchPage(HomeApp, {Key? key, required this.getBooks,})
      : super(key: key);

  final myController = TextEditingController();
  final Function getBooks;