Dependency Injection in GetX

 import "package:firebase/GetX/Controller.dart";

import "package:flutter/material.dart";
import "package:get/get.dart";

void main()
{
  runApp(MyApp());
}
class MyApp extends StatelessWidget
{
  MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return GetMaterialApp(
      title: "Dependency Injection",
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.brown,
      ),
      home: DependencyInjection(),
    );
  }
}
class DependencyInjection extends StatelessWidget
{
  DependencyInjection({super.key});

  /// My Controller instance will be created even if it is not used tag will be used
  /// to find the instance with tag name Controller disposed when it is not used but if
  /// permanent is true the instance will be alive throughout the app
  // MyController myController = Get.put(MyController(), tag: "instance1", permanent: true);

  @override
  Widget build(BuildContext context) {

    /// Instance will be created when it is used. "fenix" is similar to "permanent", the difference is that
    /// the instance is discarded when is not being used, but when it's use is needed again,
    /// Get will recreate the instance
    // Get.lazyPut(() { return MyController(); }, tag: "instance2", fenix: true);

    Get.putAsync<MyController>(() async { return await MyController(); },);

    /// Here below, permanent will be true by default and isSingleton is false
    // Get.create<MyController>(() { return MyController(); },);

    return Scaffold(
      appBar: AppBar(
        title: const Text("Dependency Injection"),
        centerTitle: true,
        backgroundColor: Colors.grey,
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            ElevatedButton(
              onPressed: () {
                /// Instance will be created with tag
                // Get.find<MyController>(tag: "instance1");

                /// Find instance
                Get.find<MyController>();

                 Get.find<MyController>().incrementCounter();
              },
              child: const Text("Click me!"),
            ),
          ],
        ),
      ),
    );
  }
}

import "package:get/get.dart";
import "package:shared_preferences/shared_preferences.dart";

class MyController extends GetxController
{
  void incrementCounter() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    int counter = (prefs.getInt("counter") ?? 0) + 1;
    print("Pressed $counter times");
    await prefs.setInt("counter", counter);
  }
}