如何在 onPressed Flutter 中声明一个变量？

Question

I am trying to create a variable in onPressed . But it says error: expected { . Can someone show an example of onPressed where a variable is initialized, declared and used?

Here is my code:

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

class TestingWidget extends StatefulWidget {
  @override
  _TestingWidgetState createState() => _TestingWidgetState();
}
var requestbody = {
  "apiKey":"z_P!EJ?dsverbtbspV3K4GxaET",
  "operationType":"register_user_otp",
  "operationData": {
    "email": "shewfwrvam@fvbtrg.com",
    "userName":"dvre",
    "accessKey":"2defr",
    "accessValue":"32rfg43v5",
    "registrationTimeStamp": 1616919213853
  }
};
var url = Uri.parse('https://script.google.com/macros/s/AKfycbz7kTROol8u509M_p9pMZ9XRnL-myVjcRQKeb9Etp_OIMPnH640vHf_0Jp2dvRIco7kOg/exec');


class _TestingWidgetState extends State<TestingWidget> {
  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: () => {
        var response = await http.post(url, body: requestbody);
        print('Response status: ${response.statusCode}');
        print('Response body: ${response.body}');
      },
      child: new Text('Click me'),
    );
  }
}

Answer 1

For anonymous functions use => or {} not both. https://dart.dev/guides/language/language-tour#anonymous-functions