Icon not changing on onPressed-CodePudding

I am working on a larger project but do not know why this small part has kept me almost a whole day.

import 'package:flutter/material.dart';

void main() {
runApp(const AllTests());
}

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

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

class _AllTestsState extends State<AllTests> {

IconData play = Icons.play_circle_filled;
onPressed(){
if(play == Icons.play_circle_filled){
    play == Icons.pause_circle_filled_rounded;

} else {
    play == Icons.play_circle_filled;
}
}

  @override
Widget build(BuildContext context) {
return MaterialApp(
  debugShowCheckedModeBanner: false,
  home: Scaffold(
    body: Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.center,
        children:  [
          IconButton(
            icon: Icon(
              play,
              size: 80,
              color: Colors.black,
            ), onPressed: () {
              setState(() {
                print('hello');
                onPressed();
              });
          },
          ),
        ],
      ),
    ),
  ),
);
}
}

I just tried removing the const keyword before AllTests() but it is still now working. I have also tried putting the function directly into the onPressed of IconButton.

the hello gets printed into the console, but the icon does not change. what could be wrong?

CodePudding user response：

Use the = operator not the ==.

onPressed() {
  if(play == Icons.play_circle_filled){
    play = Icons.pause_circle_filled_rounded;
  } else {
    play = Icons.play_circle_filled;
  }
}

CodePudding user response：

You have used the == operator instead of the = operator. use this instead:

onPressed(){
if(play == Icons.play_circle_filled){
    play = Icons.pause_circle_filled_rounded;

} else {
    play = Icons.play_circle_filled;
}
}