Simple State manager GetBuilder

main.dart

import 'package:flutter/material.dart';
import 'package:flutter_getx/my_controller.dart';
import 'package:flutter_getx/next_screen.dart';
import 'package:flutter_getx/student.dart';
import 'package:flutter_getx/unknown_route.dart';
import 'package:get/get.dart';
import 'home.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // If init property is not used in GetX<Type of Controller> then
  //create the instance of controller as follows.
  //MyController myController = Get.put(MyController());

  @override
  Widget build(BuildContext context) {
   
    // TODO: implement build
    return GetMaterialApp(
      title: "State Management",
      home: Scaffold(
        appBar: AppBar(title: Text("State Management")),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              GetBuilder<MyController>(
                init: MyController(),
                builder: (controller) {
                  return Text(
                    "The value is  ${controller.count}",
                    style: TextStyle(fontSize: 25),
                  );
                },
              ),
              SizedBox(
                height: 16,
              ),
              RaisedButton(
                child: Text("Increment"),
                onPressed: () {

                  //myController.increment();

                  // If instance of controller not created at top
               // Get.find<MyController>().increment();
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}

my_controller.dart

import 'package:flutter_getx/student.dart';
import 'package:get/get.dart';
class MyController extends GetxController
{
  var count=0;
  void increment()
  {
    count++;
    update(); // Will update the count variable on UI which uses it
  }
}