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Description:

bluetooth print plus

Introduction #
Bluetooth Print Plus is a Bluetooth plugin used to print thermal printers in Flutter,
a new mobile SDK to help developers build bluetooth thermal printer apps for both iOS and Android.

Important, important, important. First, you need to run the demo to confirm the printer command type!!!
now support tspl/tsc、cpcl、esc pos，
If this plugin is helpful to you, please give it a like，Thanks.

FAQ Support #

QQ group：904457621

TG group

Buy Me A Coffee/请我喝杯咖啡 #

Plan #

Version
plan

1.1.x
blue and tsc command, esc print image command

1.5.x
support cpcl command

2.x.x
improve esc command

3.x.x
support zpl command

Features #

Android
iOS
Description

scan
✅
✅
Starts a scan for Bluetooth Low Energy devices.

connect
✅
✅
Establishes a connection to the device.

disconnect
✅
✅
Cancels an active or pending connection to the device.

state
✅
✅
Stream of state changes for the Bluetooth Device.

Usage #
Example
To use this plugin : #

add the dependency to your pubspec.yaml file.

dependencies:
flutter:
sdk: flutter
bluetooth_print_plus:
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Add permissions for Bluetooth #
We need to add the permission to use Bluetooth and access location:
Android
In the android/app/src/main/AndroidManifest.xml let’s add:
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
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IOS
In the ios/Runner/Info.plist let’s add:
<key>NSBluetoothAlwaysUsageDescription</key>
<string>Need BLE permission</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>Need BLE permission</string>
<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
<string>Need Location permission</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>Need Location permission</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>Need Location permission</string>
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For location permissions on iOS see more at: https://developer.apple.com/documentation/corelocation/requesting_authorization_for_location_services
init a BluetoothPrint instance #
import 'package:bluetooth_print_plus/bluetooth_print_plus.dart';
import 'package:bluetooth_print/bluetooth_print_model.dart';

final _bluetoothPrintPlus = BluetoothPrintPlus.instance;
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scan #
// begin scan
_bluetoothPrintPlus.startScan(timeout: const Duration(seconds: 30));

// get devices
StreamBuilder<List<BluetoothDevice>>(
stream: _bluetoothPrintPlus.scanResults,
initialData: [],
builder: (c, snapshot) => ListView(
children: snapshot.data!.map((d) => Container(
padding: const EdgeInsets.only(left: 10, right: 10, bottom: 5),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Expanded(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(d.name ?? ''),
Text(
d.address ?? 'null',
overflow: TextOverflow.ellipsis,
style: const TextStyle(
fontSize: 12,
color: Colors.grey
),
),
const Divider(),
],
)
),
const SizedBox(width: 10,),
ElevatedButton(
onPressed: () async {
_bluetoothPrintPlus.stopScan();
_bluetoothPrintPlus.connect(d);
_device = d;
},
child: const Text("connect"),
)
],
),
)).toList(),
),
)
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connect #
await _bluetoothPrintPlus.connect(_device);
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disconnect #
await _bluetoothPrintPlus.disconnect();
or
await BluetoothPrintPlus.instance.disconnect();
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listen state #
_bluetoothPrintPlus.state.listen((state) {
print('cur device status: $state');
switch (state) {
case BluetoothPrint.CONNECTED:
setState(() {
_connected = true;
});
break;
case BluetoothPrint.DISCONNECTED:
setState(() {
_connected = false;
});
break;
default:
break;
}
});
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print (tsc command, label mode) #
final ByteData bytes = await rootBundle.load("assets/dithered-image.png");
final Uint8List image = bytes.buffer.asUint8List();
await tscCommand.cleanCommand();
await tscCommand.cls();
await tscCommand.size(width: 76, height: 130);
await tscCommand.image(image: image, x: 50, y: 60);
await tscCommand.print(1);
final cmd = await tscCommand.getCommand();
if (cmd == null) return;
BluetoothPrintPlus.instance.write(cmd);
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Troubleshooting #
error:'State restoration of CBCentralManager is only allowed for applications that have specified the "bluetooth-central" background mode'
info.plist add:
<key>NSBluetoothAlwaysUsageDescription</key>
<string>Allow App use bluetooth?</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>Allow App use bluetooth?</string>
<key>UIBackgroundModes</key>
<array>
<string>bluetooth-central</string>
<string>bluetooth-peripheral</string>
</array>
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Thanks For #

flutter_blue