bluetooth_print 2.0.0

Flutter Android iOS

A new flutter plugin project connect to bluetooth thermal printer (Gprinter).

pub package

Introduction #

BluetoothPrint is a bluetooth plugin for Flutter, a new mobile SDK to help developers build bluetooth thermal printer apps for both iOS and Android.(for example, Gprinter pt-280、pt-380、gp-1324、gp-2120 eg.)

verison #

2.0.0(flutter 1.12)
1.2.0(flutter 1.9)

Features #

AndroidiOSDescription
scanStarts a scan for Bluetooth Low Energy devices.
connectEstablishes a connection to the device.
disconnectCancels an active or pending connection to the device.
stateStream of state changes for the Bluetooth Device.
print test messageprint device test message.
print textprint custom text, support layout.
print imageprint image.
print qrcodeprint qrcode,support change size.
print barcodeprint barcode

Usage #

Example

To use this plugin :

  dependencies:
    flutter:
      sdk: flutter
    bluetooth_print:
  • init a BluetoothPrint instance
import 'package:bluetooth_print/bluetooth_print.dart';
import 'package:bluetooth_print/bluetooth_print_model.dart';


BluetoothPrint bluetoothPrint = BluetoothPrint.instance;

scan #

// begin scan
bluetoothPrint.startScan(timeout: Duration(seconds: 4));

// get devices
StreamBuilder<List<BluetoothDevice>>(
    stream: bluetoothPrint.scanResults,
    initialData: [],
    builder: (c, snapshot) => Column(
      children: snapshot.data.map((d) => ListTile(
        title: Text(d.name??''),
        subtitle: Text(d.address),
        onTap: () async {
          setState(() {
            _device = d;
          });
        },
        trailing: _device!=null && _device.address == d.address?Icon(
          Icons.check,
          color: Colors.green,
        ):null,
      )).toList(),
    ),
  ),

connect #

await bluetoothPrint.connect(_device);

disconnect #

await bluetoothPrint.disconnect();

listen state #

      bluetoothPrint.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;
      }
    });
    Map<String, dynamic> config = Map();
    List<LineText> list = List();
    list.add(LineText(type: LineText.TYPE_TEXT, content: 'A Title', weight: 1, align: LineText.ALIGN_CENTER,linefeed: 1));
    list.add(LineText(type: LineText.TYPE_TEXT, content: 'this is conent left', weight: 0, align: LineText.ALIGN_LEFT,linefeed: 1));
    list.add(LineText(type: LineText.TYPE_TEXT, content: 'this is conent right', align: LineText.ALIGN_RIGHT,linefeed: 1));
    list.add(LineText(linefeed: 1));
    list.add(LineText(type: LineText.TYPE_BARCODE, content: 'A12312112', size:10, align: LineText.ALIGN_CENTER, linefeed: 1));
    list.add(LineText(linefeed: 1));
    list.add(LineText(type: LineText.TYPE_QRCODE, content: 'qrcode i', size:10, align: LineText.ALIGN_CENTER, linefeed: 1));
    list.add(LineText(linefeed: 1));

    ByteData data = await rootBundle.load("assets/images/guide3.png");
    List<int> imageBytes = data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
    String base64Image = base64Encode(imageBytes);
    list.add(LineText(type: LineText.TYPE_IMAGE, content: base64Image, align: LineText.ALIGN_CENTER, linefeed: 1));

    await bluetoothPrint.printReceipt(config, list);
    Map<String, dynamic> config = Map();
    config['width'] = 40; // 标签宽度,单位mm
    config['height'] = 70; // 标签高度,单位mm
    config['gap'] = 2; // 标签间隔,单位mm

    // x、y坐标位置,单位dpi,1mm=8dpi
    List<LineText> list = List();
    list.add(LineText(type: LineText.TYPE_TEXT, x:10, y:10, content: 'A Title'));
    list.add(LineText(type: LineText.TYPE_TEXT, x:10, y:40, content: 'this is content'));
    list.add(LineText(type: LineText.TYPE_QRCODE, x:10, y:70, content: 'qrcode i\n'));
    list.add(LineText(type: LineText.TYPE_BARCODE, x:10, y:190, content: 'qrcode i\n'));

    List<LineText> list1 = List();
    ByteData data = await rootBundle.load("assets/images/guide3.png");
    List<int> imageBytes = data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
    String base64Image = base64Encode(imageBytes);
    list1.add(LineText(type: LineText.TYPE_IMAGE, x:10, y:10, content: base64Image,));

    await bluetoothPrint.printLabel(config, list);
    await bluetoothPrint.printLabel(config, list1);

Troubleshooting #

ios import third party library

[Please Read link: https://stackoverflow.com/questions/19189463/cocoapods-podspec-issue)
*.podspec add:

# .a filename must begin with lib, eg. 'libXXX.a'
s.vendored_libraries = '**/*.a'

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>

Thanks For #

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popularity

A new flutter plugin project connect to bluetooth thermal printer (Gprinter).

Repository (GitHub)
View/report issues

Documentation

API reference

Uploader

thon.ju@gmail.com

License

MIT (LICENSE)

Dependencies

flutter, json_annotation, rxdart

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Packages that depend on bluetooth_print