yjy_flutter_bluetooth_printer 是一个用于在 Flutter 应用中连接和打印到蓝牙打印机的插件。以下是使用该插件的基本步骤和示例代码。

1. 添加依赖

首先，在 pubspec.yaml 文件中添加 yjy_flutter_bluetooth_printer 插件的依赖：

dependencies:
  flutter:
    sdk: flutter
  yjy_flutter_bluetooth_printer: ^1.0.0  # 请使用最新版本

然后运行 flutter pub get 来安装依赖。

2. 配置权限

在 Android 和 iOS 上，你需要在项目的配置文件中添加必要的权限。

Android

在 android/app/src/main/AndroidManifest.xml 文件中添加以下权限：

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

iOS

在 ios/Runner/Info.plist 文件中添加以下权限：

<key>NSBluetoothAlwaysUsageDescription</key>
<string>需要蓝牙权限来连接打印机</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>需要蓝牙权限来连接打印机</string>

3. 使用插件

在你的 Dart 代码中，导入并开始使用 yjy_flutter_bluetooth_printer 插件。

import 'package:flutter/material.dart';
import 'package:yjy_flutter_bluetooth_printer/yjy_flutter_bluetooth_printer.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: BluetoothPrinterScreen(),
    );
  }
}

class BluetoothPrinterScreen extends StatefulWidget {
  [@override](/user/override)
  _BluetoothPrinterScreenState createState() => _BluetoothPrinterScreenState();
}

class _BluetoothPrinterScreenState extends State<BluetoothPrinterScreen> {
  List<BluetoothDevice> _devices = [];
  BluetoothDevice? _selectedDevice;

  [@override](/user/override)
  void initState() {
    super.initState();
    _scanDevices();
  }

  Future<void> _scanDevices() async {
    try {
      List<BluetoothDevice> devices = await YjyFlutterBluetoothPrinter.scanDevices();
      setState(() {
        _devices = devices;
      });
    } catch (e) {
      print("Error scanning devices: $e");
    }
  }

  Future<void> _connectToDevice(BluetoothDevice device) async {
    try {
      await YjyFlutterBluetoothPrinter.connect(device);
      setState(() {
        _selectedDevice = device;
      });
      print("Connected to ${device.name}");
    } catch (e) {
      print("Error connecting to device: $e");
    }
  }

  Future<void> _printTest() async {
    if (_selectedDevice == null) {
      print("No device selected");
      return;
    }

    try {
      await YjyFlutterBluetoothPrinter.printText("Hello, Bluetooth Printer!");
      print("Print successful");
    } catch (e) {
      print("Error printing: $e");
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Bluetooth Printer Example'),
      ),
      body: Column(
        children: [
          ElevatedButton(
            onPressed: _scanDevices,
            child: Text('Scan Devices'),
          ),
          Expanded(
            child: ListView.builder(
              itemCount: _devices.length,
              itemBuilder: (context, index) {
                BluetoothDevice device = _devices[index];
                return ListTile(
                  title: Text(device.name ?? 'Unknown Device'),
                  subtitle: Text(device.address),
                  onTap: () => _connectToDevice(device),
                );
              },
            ),
          ),
          ElevatedButton(
            onPressed: _printTest,
            child: Text('Print Test'),
          ),
        ],
      ),
    );
  }
}