flutter_ttc_ble 0.0.2

Android BLE(Bluetooth Low Energy) Flutter plugin.

example/lib/main.dart

import 'dart:async';
import 'dart:typed_data';

import 'package:convert/convert.dart';
import 'package:flutter/material.dart';
import 'package:flutter_ttc_ble/flutter_ttc_ble.dart';

import 'communication.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> with WidgetsBindingObserver {
  List<BLEDevice> _dataList = <BLEDevice>[];

  @override
  void initState() {
    super.initState();
    print('main -> initState()');
    WidgetsBinding.instance.addObserver(this);

    initPlatformState();
  }

  // Platform messages are asynchronous, so we initialize in an async method.
  Future<void> initPlatformState() async {
    //TODO BLE 插件初始化
    FlutterTtcBle.init();

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;
  }

  @override
  void didChangeDependencies() {
    print('main -> didChangeDependencies()');
    super.didChangeDependencies();
  }

  @override
  void didUpdateWidget(MyApp oldWidget) {
    //当树rebuid的时候会调用该方法
    print('main -> didUpdateWidget()');
    super.didUpdateWidget(oldWidget);
  }

  @override
  void deactivate() {
    //当State对象从树中被移除时，会调用此回调。
    print('main -> deactivate()');
    super.deactivate();
  }

  @override
  void dispose() {
    //当State对象从树中被永久移除时调用；通常在此回调中释放资源。
    print('main -> dispose()');
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  //Flutter生命周期：https://blog.csdn.net/brycegao321/article/details/86583223
  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    print('main -> didChangeAppLifecycleState() - state=$state');
    super.didChangeAppLifecycleState(state);
  }

  @override
  Widget build(BuildContext context) {
    //print('main -> build()');
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter BLE Demo V1.0'),
        ),
        body: RefreshIndicator(
          onRefresh: _refresh,
          child: ListView.builder(
            itemCount: _dataList.length,
            itemBuilder: (context, index) {
              return _buildRow(_dataList[index]);
            },
          ),
        ),
      ),
    );
  }

  ///下拉刷新（扫描设备）
  Future<Null> _refresh() async {
    setState(() {
      _dataList.clear();
    });

    FlutterTtcBle.startLeScan((device) {
      setState(() {
        //刷新UI要在setState()方法内进行
        //为了防止列表中设备重复，这里判断一下
        if (!_dataList.contains(device)) _dataList.add(device);
      });
    });

    await Future.delayed(Duration(seconds: 5), () {
      print('refresh() - delayed 5s');
      setState(() {
        //
      });
    });
  }

  ///加载列表项
  Widget _buildRow(BLEDevice device) {
    // 这里使用 Builder 避免异常：Navigator operation requested with a context that does not include a Navigator.
    // 参考 https://blog.csdn.net/nimeghbia/article/details/84388725

    return Builder(
      builder: (context) => new ListTile(
            title: new Text(
              device.name != null ? device.name : "Unknown Device",
            ),
            subtitle: new Text(
              '${device.deviceId}'
                  '\nAdvertisData=${_advertisDataToString(device.advertisData)}'
                  '\nServiceUUIDs=${device.advertisServiceUUIDs}'
                  '\nServiceData=${_serviceDataToString(device.serviceData)}',
            ),
            onTap: () {
              _toCommPage(context, device);
            },
          ),
    );
  }

  String _advertisDataToString(Uint8List advertisData) {
    return advertisData == null ? "" : hex.encode(advertisData);
  }

  String _serviceDataToString(Map<String, Uint8List> serviceData) {
    StringBuffer sb = StringBuffer('{');
    int i = 0;
    serviceData.forEach((uuid, data) => (String uuid, Uint8List data) {
          sb.write("$uuid: ${hex.encode(data)}");
          if (i < serviceData.length - 1) {
            sb.write(', ');
          }
          i++;
        });
    sb.write('}');
    return sb.toString();
  }

  ///跳转到数据交互页面
  void _toCommPage(BuildContext context, BLEDevice device) async {
    final result = await Navigator.push(
      context,
      MaterialPageRoute(builder: (BuildContext context) => CommPage(device)),
    );

    print('从数据交互页面返回 $result');

    ///这是在页面底部显示一个弹出提示
    //Scaffold.of(context).showSnackBar(SnackBar(content: Text(result)));
    //TODO 监听平台消息
  }
}