how to focus on the page flutter adn dismiss the keyboard code example

Example 1: close keyboard on button click flutter

class _HomeState extends State<Home> {
 var currentFocus;
    
 unfocus() {
    currentFocus = FocusScope.of(context);

    if (!currentFocus.hasPrimaryFocus) {
      currentFocus.unfocus();
    }
  }
  
Widget build(BuildContext context) {
    return GestureDetector(
      onTap: unfocus,
      child: Scaffold(...)
      )
     }

Example 2: remove focus textfield flutter

// main.dart
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () {
        FocusScopeNode currentFocus = FocusScope.of(context);

        if (!currentFocus.hasPrimaryFocus) {
          currentFocus.unfocus();
        }
      },
      child: MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: MyHomePage(),
      ),
    );
  }
}