I’m creating an app with Bluetooth connection and it’s having errors while creating a widget with a list that I created to put all Bluetooth devices connect. Looks like the Flutter is trying to create an infinite widget, please someone can help me? I don’t know how to solve it. The code below is from the Bluetooth screen that is linked to the settings in the main.dart menu:
import 'package:flutter/material.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart';
class BluetoothScreen extends StatefulWidget {
@override
_BluetoothScreenState createState() => _BluetoothScreenState();
}
class _BluetoothScreenState extends State<BluetoothScreen> {
List<BluetoothDevice> devicesList = [];
BluetoothDevice? connectedDevice;
bool isScanning = false;
@override
void initState() {
super.initState();
scanForDevices();
}
void scanForDevices() async {
setState(() {
isScanning = true;
devicesList.clear();
});
FlutterBluePlus.startScan(timeout: Duration(seconds: 4));
FlutterBluePlus.scanResults.listen((results) {
setState(() {
devicesList = results.map((r) => r.device).toList();
});
});
await Future.delayed(Duration(seconds: 4));
FlutterBluePlus.stopScan();
setState(() {
isScanning = false;
});
}
void connectToDevice(BluetoothDevice device) async {
await device.connect();
setState(() {
connectedDevice = device;
});
}
void disconnectFromDevice() async {
if (connectedDevice != null) {
await connectedDevice!.disconnect();
setState(() {
connectedDevice = null;
});
}
}
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
if (isScanning)
Flexible(
child: Center(child: CircularProgressIndicator()),
)
else
Flexible(
child: devicesList.isEmpty
? Center(child: Text('Nenhum dispositivo encontrado'))
: ListView.builder(
itemCount: devicesList.length,
itemBuilder: (context, index) {
final device = devicesList[index];
return ListTile(
title: Text(device.name.isNotEmpty
? device.name
: 'Dispositivo sem nome'),
subtitle: Text(device.id.toString()),
onTap: () {
connectToDevice(device);
},
);
},
),
),
if (connectedDevice != null)
Padding(
padding: const EdgeInsets.all(10.0),
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
Text('Conectado a ${connectedDevice!.name}'),
ElevatedButton(
onPressed: disconnectFromDevice,
child: Text('Desconectar'),
),
],
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: ElevatedButton(
onPressed: scanForDevices,
child: Text('Escanear Dispositivos'),
),
),
],
);
}
}
This is what appears when I try debug it:
The relevant error-causing widget was:
Column Column:file:///C:/Users/marco/Desktop/projetos/Aplicativo%20Apollodi/base_apollodi/lib/screens/bluetooth_screen.dart:59:12
When the exception was thrown, this was the stack:
The following RenderObject was being processed when the exception was fired: RenderFlex#68e4a relayoutBoundary=up15 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0); flex=null; fit=null (can use size)
constraints: BoxConstraints(0.0<=w<=360.0, 0.0<=h<=Infinity)
size: MISSING
direction: vertical
mainAxisAlignment: start
mainAxisSize: max
crossAxisAlignment: center
verticalDirection: down
child 1: RenderPositionedBox#34313 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0); flex=1; fit=FlexFit.loose
constraints: MISSING
size: MISSING
alignment: Alignment.center
textDirection: ltr
widthFactor: expand
heightFactor: expand
child: RenderSemanticsAnnotations#12ee4 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0)
constraints: MISSING
size: MISSING
child: RenderConstrainedBox#4c22a NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: <none>
constraints: MISSING
size: MISSING
additionalConstraints: BoxConstraints(36.0<=w<=Infinity, 36.0<=h<=Infinity)
child: RenderCustomPaint#bdea4 NEEDS-LAYOUT NEEDS-PAINT
parentData: <none>
constraints: MISSING
size: MISSING
painter: _CircularProgressIndicatorPainter#043bd()
child 2: RenderPadding#39626 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0); flex=null; fit=null
constraints: MISSING
size: MISSING
padding: EdgeInsets.all(8.0)
textDirection: ltr
child: RenderSemanticsAnnotations#a3624 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0)
constraints: MISSING
semantic boundary
size: MISSING
child: _RenderInputPadding#894c9 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: <none>
constraints: MISSING
size: MISSING
child: RenderConstrainedBox#5ee88 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0)
constraints: MISSING
size: MISSING
additionalConstraints: BoxConstraints(64.0<=w<=Infinity, 40.0<=h<=Infinity)
RenderObject: RenderFlex#68e4a relayoutBoundary=up15 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0); flex=null; fit=null (can use size)
constraints: BoxConstraints(0.0<=w<=360.0, 0.0<=h<=Infinity)
size: MISSING
direction: vertical
mainAxisAlignment: start
mainAxisSize: max
crossAxisAlignment: center
verticalDirection: down
child 1: RenderPositionedBox#34313 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0); flex=1; fit=FlexFit.loose
constraints: MISSING
size: MISSING
alignment: Alignment.center
textDirection: ltr
widthFactor: expand
heightFactor: expand
child: RenderSemanticsAnnotations#12ee4 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0)
constraints: MISSING
size: MISSING
child: RenderConstrainedBox#4c22a NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: <none>
constraints: MISSING
size: MISSING
additionalConstraints: BoxConstraints(36.0<=w<=Infinity, 36.0<=h<=Infinity)
child: RenderCustomPaint#bdea4 NEEDS-LAYOUT NEEDS-PAINT
parentData: <none>
constraints: MISSING
size: MISSING
painter: _CircularProgressIndicatorPainter#043bd()
child 2: RenderPadding#39626 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0); flex=null; fit=null
constraints: MISSING
size: MISSING
padding: EdgeInsets.all(8.0)
textDirection: ltr
child: RenderSemanticsAnnotations#a3624 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0)
constraints: MISSING
semantic boundary
size: MISSING
child: _RenderInputPadding#894c9 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: <none>
constraints: MISSING
size: MISSING
child: RenderConstrainedBox#5ee88 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
parentData: offset=Offset(0.0, 0.0)
constraints: MISSING
size: MISSING
additionalConstraints: BoxConstraints(64.0<=w<=Infinity, 40.0<=h<=Infinity)
════════ Exception caught by rendering library ═════════════════════════════════
RenderBox was not laid out: RenderFlex#47094 relayoutBoundary=up14 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 2165 pos 12: 'hasSize'
The relevant error-causing widget was:
I tried to modify the column with an expanded, with a flexible, but nothing worked
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