Flutter功能未知插件zebrautility的潜在用途探索

Flutter ZebraUtility 插件的潜在用途探索

1. 插件简介

ZebraUtility 是一个用于在 Flutter 项目中轻松与 Zebra 打印机交互的插件。它支持以下功能：

• 在 Android 和 iOS 上发现蓝牙和 Wi-Fi 打印机（iOS 仅支持蓝牙打印机）。
• 连接和断开打印机。
• 设置 ZPL 打印机的媒体类型、打印浓度、校准命令，而无需编写任何 ZPL 代码。
• 旋转 ZPL 打印内容而不改变原始 ZPL 代码。

2. 安装步骤

Android

在 build.gradle 文件（模块级别）中添加以下代码：

android {
    packagingOptions {
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/DEPENDENCIES'
    }
}

iOS

在 info.plist 文件中添加以下配置：

• 添加 Supported external accessory protocols 并添加 com.zebra.rawport。
• 添加 Privacy - Local Network Usage Description。

3. 示例 Demo

以下是一个完整的示例代码，展示了如何使用 ZebraUtility 插件与 Zebra 打印机进行交互。

import 'package:flutter/material.dart';
import 'package:zebrautility/ZebraPrinter.dart';
import 'package:zebrautility/zebrautility.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(primarySwatch: Colors.blue),
      home: const MyHomePage(title: "Zebra Printer Example"),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key key, this.title}) : super(key: key);
  final String title;

  [@override](/user/override)
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  ZebraPrinter zebraPrinter;
  bool searchingWifi = false;
  bool searchingBluetooth = false;
  List<AvailablePrinter> availablePrinters = <AvailablePrinter>[];
  AvailablePrinter printer = AvailablePrinter();

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

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(widget.title)),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ElevatedButton(
              onPressed: () => startDiscovery(),
              child: const Text('Discover Printers'),
            ),
            ElevatedButton(
              onPressed: () => connectToPrinter(),
              child: const Text('Connect to Printer'),
            ),
            ElevatedButton(
              onPressed: () => disconnectFromPrinter(),
              child: const Text('Disconnect from Printer'),
            ),
            ElevatedButton(
              onPressed: () => setMediaType(),
              child: const Text('Set Media Type'),
            ),
            ElevatedButton(
              onPressed: () => calibratePrinter(),
              child: const Text('Calibrate Printer'),
            ),
            ElevatedButton(
              onPressed: () => setDarkness(),
              child: const Text('Set Darkness'),
            ),
            ElevatedButton(
              onPressed: () => printZpl(),
              child: const Text('Print ZPL'),
            ),
            ElevatedButton(
              onPressed: () => rotateZpl(),
              child: const Text('Rotate ZPL'),
            ),
          ],
        ),
      ),
    );
  }

  void initializePrinter() async {
    zebraPrinter ??= await Zebrautility.getPrinterInstance(
      onPrinterFound: (name, ipAddress, isWifi) {
        debugPrint("PrinterFound :$name$ipAddress${isWifi.toString()}");
        if (searchingWifi && isWifi) {
          availablePrinters.add(AvailablePrinter(name: name, ipAddress: ipAddress, isWifi: isWifi));
        }
        if (searchingBluetooth && !isWifi) {
          availablePrinters.add(AvailablePrinter(name: name, ipAddress: ipAddress, isWifi: isWifi));
        }
      },
      onPrinterDiscoveryDone: () async {
        debugPrint("Discovery Done");
        await Future.delayed(const Duration(seconds: 1));
      },
      onDiscoveryError: (int errorCode, String error) {
        debugPrint("Discovery Failed $error");
      },
      onChangePrinterStatus: (status, color) {
        status = status == "Done" ? "Connected" : status;
        List<String> statuses = ["R", "Y", "G"];
        int statusID = statuses.indexOf(color);
        debugPrint("change bt printer status: $status$color");
        if (statusID == 0) {
          printer = null;
        } else if (statusID == 2) {
          debugPrint("Successfully connected to ${printer.ipAddress}");
        }
      },
      onPermissionDenied: () {
        debugPrint("Permission Deny.");
      },
    );
  }

  void startDiscovery() {
    setState(() {
      searchingWifi = true;
      searchingBluetooth = true;
    });
    zebraPrinter.discoveryPrinters();
  }

  void connectToPrinter() {
    if (availablePrinters.isNotEmpty) {
      AvailablePrinter selectedPrinter = availablePrinters.first;
      if (selectedPrinter.isWifi) {
        zebraPrinter.connectToPrinter(selectedPrinter.ipAddress);
      } else {
        zebraPrinter.connectToPrinter(selectedPrinter.ipAddress, isBluetooth: true);
      }
    }
  }

  void disconnectFromPrinter() {
    zebraPrinter.disconnect();
    printer = null;
  }

  void setMediaType() {
    zebraPrinter.setMediaType(EnumMediaType.BlackMark);
  }

  void calibratePrinter() {
    zebraPrinter.calibratePrinter();
  }

  void setDarkness() {
    zebraPrinter.setDarkness(25);
  }

  void printZpl() {
    String zpl = "^XA^FO50,50^A0N,50,50^FDHello, World!^FS^XZ";
    zebraPrinter.print(zpl);
  }

  void rotateZpl() {
    zebraPrinter.rotate();
  }
}

class AvailablePrinter {
  String name;
  String ipAddress;
  bool isWifi;

  AvailablePrinter({this.name, this.ipAddress, this.isWifi = false});
}