Flutter – how i can use search delegate correctly

I have reviewed your code and found that you were trying to use the showSearch function with a context that does not have a Navigator in its widget tree.

In your code, you are using a nested MaterialApp, which can lead to issues. There should only be one MaterialApp at the root of your widget tree. Here’s how you can fix your code:

1. Remove the nested MaterialApp.
2. Use showSearch with the correct context.

I have modified your code with some additions, feel free to makes changes and see if it works.

Code:

import 'package:flutter/material.dart';

void main() {
  runApp(Rekomo2());
}

class Rekomo2 extends StatefulWidget {
  Rekomo2({super.key});

  @override
  State<Rekomo2> createState() => _Rekomo2State();
}

class _Rekomo2State extends State<Rekomo2> {
  int curindex = 0;
  final screen = [Chats(), Groups(), NearMe(), Status(), Favourite()];

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        floatingActionButton: Column(
          crossAxisAlignment: CrossAxisAlignment.end,
          mainAxisAlignment: MainAxisAlignment.end,
          children: [
            FloatingActionButton(
              backgroundColor: Colors.purple[300],
              onPressed: () {
                showSearch(context: context, delegate: Search());
              },
              child: const Icon(
                Icons.search,
                color: Colors.white,
                size: 30,
              ),
            ),
            Container(
              height: 10,
            ),
            FloatingActionButton(
              backgroundColor: Colors.purple[300],
              onPressed: () {},
              child: const Icon(
                Icons.add,
                color: Colors.white,
                size: 30,
              ),
            ),
          ],
        ),
        appBar: AppBar(
          actions: [
            IconButton(
                onPressed: () {
                  showSearch(context: context, delegate: Search());
                },
                icon: Icon(Icons.search, size: 30, color: Colors.purple[300])),
          ],
          leading: Builder(
            builder: (context) => IconButton(
              onPressed: () {
                Scaffold.of(context).openDrawer();
              },
              icon: const Icon(Icons.menu),
              color: Colors.purple[300],
            ),
          ),
          backgroundColor: Colors.white,
          title: Text(
            "Rekomo2",
            style: TextStyle(
                fontSize: 25, fontWeight: FontWeight.bold, color: Colors.purple[300]),
          ),
        ),
        bottomNavigationBar: BottomNavigationBar(
          currentIndex: curindex,
          onTap: (value) {
            setState(() {
              curindex = value;
            });
          },
          selectedItemColor: Colors.purple[600],
          type: BottomNavigationBarType.fixed,
          showSelectedLabels: true,
          showUnselectedLabels: false,
          items: const [
            BottomNavigationBarItem(icon: Icon(Icons.chat), label: "Chats"),
            BottomNavigationBarItem(icon: Icon(Icons.group), label: "Groups"),
            BottomNavigationBarItem(icon: Icon(Icons.location_on_outlined), label: "People Near Me"),
            BottomNavigationBarItem(icon: Icon(Icons.switch_access_shortcut_sharp), label: "Status"),
            BottomNavigationBarItem(icon: Icon(Icons.star), label: "Favourite"),
          ],
        ),
        drawer: const Drawer(),
        body: screen[curindex],
      ),
    );
  }
}

class Search extends SearchDelegate {
  List searchResults = ["devil", "karma", "reem", "ahmed", "moaa"];

  @override
  List<Widget>? buildActions(BuildContext context) {
    return [
      IconButton(
        onPressed: () {
          query = "";
        },
        icon: Icon(Icons.close),
      ),
    ];
  }

  @override
  Widget? buildLeading(BuildContext context) {
    return IconButton(
      onPressed: () {
        close(context, null);
      },
      icon: Icon(Icons.arrow_back),
    );
  }

  @override
  Widget buildResults(BuildContext context) {
    return Center(child: Text(query));
  }

  @override
  Widget buildSuggestions(BuildContext context) {
    final suggestions = query.isEmpty
        ? []
        : searchResults.where((element) => element.contains(query)).toList();

    return ListView.builder(
      itemCount: suggestions.length,
      itemBuilder: (context, index) {
        return ListTile(
          title: Text(suggestions[index]),
          onTap: () {
            query = suggestions[index];
            showResults(context);
          },
        );
      },
    );
  }
}

class Chats extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: Text('Chats'));
  }
}

class Groups extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: Text('Groups'));
  }
}

class NearMe extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: Text('People Near Me'));
  }
}

class Status extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: Text('Status'));
  }
}

class Favourite extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: Text('Favourite'));
  }
}