TextButton is automatically invoked when the dropDown menu item is changed - flutter

Question

Here goes my code ,
I am using the TextButton to update the order ,But after every change in the dropdown item, onPress is automatically invoked and the function updateOrder is automatically invoked
import 'package:admin/constants/Constants.dart';
import 'package:admin/model/order_model.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:dropdown_button2/dropdown_button2.dart';
import 'package:flutter/material.dart';
class DetailsScreen extends StatefulWidget {
const DetailsScreen({Key? key}) : super(key: key);
#override
State<DetailsScreen> createState() => _DetailsScreenState();
}
class _DetailsScreenState extends State<DetailsScreen> {
List<String> _dropDownQuantities = [Pending, Confirmed, Rejected, Success];
late OrderModel order;
late String selectedStatus = order.status;
#override
Widget build(BuildContext context) {
order = ModalRoute.of(context)?.settings.arguments as OrderModel;
return Scaffold(
appBar: AppBar(
actions: [],
title: Text("Order Details"),
),
body: Column(children: [
Text(order.id),
DropdownButtonHideUnderline(
child: DropdownButton2<String>(
value: selectedStatus,
items: _dropDownQuantities
.map((e) => DropdownMenuItem<String>(
child: Text(e),
value: e,
))
.toList(),
onChanged: (value) {
setState(() {
selectedStatus = value;
});
},
)),
TextButton(onPressed: updateOrder(order, selectedStatus), child: Text("Confirm")),
]));
}
}
updateOrder(OrderModel order, String selected) {
print("I am executed");
}
So whenever i change the dropDown menu,
I am executed is printed in the console.
Edit:
But when i used the container with InkWell it was working fine. Why not working with TextButton ?

Answer 1

You are directly calling the method on build, you can create an inline anonymous function to handle this.
TextButton(
onPressed: ()=> updateOrder(order, selectedStatus),
child: Text("Confirm")),
onPressed Called when the button is tapped or otherwise activated.
While we use onPressed:method() call on every build, on dropDown onChanged we use setState, and it rebuilds the UI and onPressed:method() call again.
What we need here is to pass a function(VoidCallback) that will trigger while we tap on the button. We provide it like,
onPressed:(){
myMethod();
}
More about TextButton.