Flutter Plugin 自定义插件

Flutter Plugin 自定义插件

1. 生成Flutter plugin 。plugin中代码就不贴了，买的二维码打印机，对其进行配置和修改
2. 在 MainActivity.kt 中，注册 BTPrinterPlugin（）

class MainActivity: FlutterActivity() {override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {isterWith(flutterEngine)flutterEngine.plugins.add(BTPrinterPlugin())    // assemble bt printer plugin  自己写的plugin}，
}

3. 报错的地方，鼠标悬浮，按需引入包
4. Flutter 中的工具类

import 'package:flutter/services.dart';/// 打印标签, 单例类
class PrinterPlugin {/// arespace.bluetooth/bt-printer-plugin  plugin中定义的 MethodChannel namestatic const MethodChannel _methodChannel = const MethodChannel(&#arespace.bluetooth/bt-printer-plugin');/// arespace.bluetooth/bt-printer-plugin/print-result  plugin中定义的 EventChannel namestatic const EventChannel _eventChannel = const EventChannel( &#arespace.bluetooth/bt-printer-plugin/print-result');static PrinterPlugin _instance;static Function eventCallBack;factory PrinterPlugin(Function event) {if (_instance == null) _instance = new PrinterPlugin._internal();PrinterPlugin.eventCallBack = event;return _instance;}PrinterPlugin._internal() {// 初始化_iveBroadcastStream().listen(_onEvent);}/// plugin 中打印的回调void _onEvent(Object event) {eventCallBack(event);}///拿到蓝牙设备，调用plugin中的 getBtDevices 方法getBtDevices() async {return await _methodChannel.invokeMethod('getBtDevices');}///连接打印机，调用plugin中的 connectPrinter 方法connectPrinter(String address) async {return await _methodChannel.invokeMethod('connectPrinter', {'address': address});}

5. 使用

  PrinterPlugin _printerPlugin = PrinterPlugin(printerPluginEvent);/// 打印 回调Ïstatic printerPluginEvent(event) {///dosomething}/// 获取蓝牙设备getBtDevices() async {String result = '';try {result = await _BtDevices();} catch (err) {print('getBtDevices err----->>>>>>>>>>>>>>>$err');}print('getBtDevices----->>>>>>>>>>>>>>>$result');}/// 调用 连接打印机函数connectPrinter(addr) async {String result = '';try {result = await _tPrinter(addr);} catch (err) {print('connectPrinter err----->>>>>>>>>>>>>>>${err}');}print('connectPrinter----->>>>>>>>>>>>>>>$result');}