Flutter打印功能插件talabi_printer的使用

Flutter打印功能插件talabi_printer的使用

本项目是一个新的Flutter插件项目，用于实现打印功能。该插件包含适用于Android和iOS平台的特定实现代码。

开始使用

要开始使用此插件，您可以参考以下示例代码来了解如何在您的Flutter应用中集成和使用talabi_printer插件。

示例代码

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

import 'package:flutter/services.dart';
import 'package:talabi_printer/talabi_printer.dart';
import 'foreground_service.dart'; // 引入前台服务类

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

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  [@override](/user/override)
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String _platformVersion = '未知';
  int? _printerStatus;
  int _printingCount = 0;
  String _error = '';
  bool _printing = false;
  bool _printingInLoop = false;

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

  // 平台消息是异步的，因此我们在异步方法中初始化
  Future<void> initPlatformState() async {
    // 平台消息可能会失败，所以我们使用try/catch处理PlatformException。
    // 我们还处理消息可能返回null的情况。
    try {
      final printer = TalabiPrinter();
      _platformVersion = await printer.getPlatformVersion() ?? '未知平台版本';
    } on PlatformException {
      _platformVersion = '获取平台版本失败。';
    }

    try {
      final printer = TalabiPrinter();
      _printerStatus = await printer.getStatus();
    } on PlatformException catch (e) {
      _error = '${e.code}: ${e.message ?? ''} ${e.details ?? ''}';
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('插件示例应用'),
        ),
        body: Center(
          child: Column(
            children: [
              Text('运行于: $_platformVersion\n'),
              Text(
                '打印机状态: ${_printerStatus ?? "未知打印机状态"}\n',
              ),
              if (_error.isNotEmpty) Text('打印机错误: $_error\n'),
              Text(
                '打印次数: $_printingCount',
              ),
              const SizedBox(
                height: 30,
              ),
              _printing
                  ? const CircularProgressIndicator()
                  : ElevatedButton.icon(
                      onPressed: _print,
                      icon: const Icon(Icons.print),
                      label: const Text('打印'),
                    ),
              const SizedBox(
                height: 30,
              ),
              _printingInLoop
                  ? const CircularProgressIndicator()
                  : ElevatedButton.icon(
                      onPressed: _loopPrinting,
                      icon: const Icon(Icons.print),
                      label: const Text('循环打印'),
                    ),
              const SizedBox(
                height: 30,
              ),
              ElevatedButton.icon(
                onPressed: () => setState(() {
                  _printingInLoop = false;
                }),
                icon: const Icon(Icons.stop),
                label: const Text('停止打印'),
              ),
              const SizedBox(
                height: 30,
              ),
              ElevatedButton(
                  onPressed: () async {
                    await ForegroundService.startForegroundService();
                  },
                child: const Text('启动前台服务'),
              )
            ],
          ),
        ),
      ),
    );
  }

  Future<Uint8List> readAssetBytes(String asset) async {
    final data = await rootBundle.load(asset);
    return data.buffer.asUint8List();
  }

  Future<void> _print() async {
    setState(() {
      _printing = true;
    });
    try {
      final printer = TalabiPrinter();
      for(int i=0; i<1; ++i) {
        // await ForegroundService.wakeScreen(); // 可选的唤醒屏幕操作
        await printer.wakeScreen();
        await printer.setGray(-1);
        await printer.printText('TALABI START', fontBold: true, fontSize: 36, align: 'center');
        await printer.feedLine(1, "solid");
        await printer.feedLine(1, "empty");
        await printer.feedLine(1, "dotted");

        int count = 2;
        await printer.addText('$count', align: 'right', fontBold: true, fontSize: 36);
        await printer.addText('X\t\t\t');
        await printer.printText('מוצר', fontBold: true, fontSize: 30, isUnderline: true);

        await printer.addText('ימין''\n', align: 'right');
        await printer.addText('מרכז''\n', align: 'center');
        await printer.printText('שמאל''\n', align: 'left');
        await printer.printText('ITALIC', align: 'center', isItalic: true);
        await printer.printText('UNDERLINE', align: 'center', isUnderline: true);
        await printer.printText('STRIKE THROUGH', align: 'center', isStrikethrough: true);
        await printer.addText('SPACE BETWEEN WORDS', wordSpacing: 10);
        await printer.addTextLeftRight('Left Large', 'Right Large', fontSize: 36, fontBold: true);
        await printer.addTextLeftCenterRight('Left', 'Center', 'Right', fontSize: 20, fontBold: false);
        // await _talabiPrinterPlugin.addBarCode('Talabi Orders');
        // await _talabiPrinterPlugin.addQrCode('Talabi Orders LTD');
        // await _talabiPrinterPlugin.addImage(await readAssetBytes('assets/talabi.png'));

        await printer.feedLine(1, "solid");
        await printer.feedLine(1, "empty");
        await printer.printText('TALABI END', fontSize: 36, align: 'center', fontBold: true);
      }
      _printerStatus = await printer.print();
    } on PlatformException catch (e) {
      _error = '${e.code}: ${e.message ?? ''} ${e.details ?? ''}';
    } catch (error) {
      _error = error.toString();
    } finally {
      setState(() {
        _printing = false;
        ++_printingCount;
      });
    }
  }

  void _loopPrinting() {
    setState(() {
      _printingInLoop = true;
    });
    Timer.periodic(const Duration(seconds: 20), (timer) async {
      if (!_printingInLoop) {
        timer.cancel();
      } else {
        await _print();
      }
    });
  }
}