日更挑战-Flutter尝试插件开发

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越不懂的越爱装

大家都同等:IT世界没有难不难,只有是否了解过

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挑战目录

创建Flutter插件项目

同创建Flutter项目类似，但是选择项目类型的时候要选择Flutter plugin项目

创建flutter插件项目

• 创建出来的项目主要目录有

  
  
  image.png
  1. android：实现插件安卓部分
  2. example：示例项目，将其他3个的实现用于该处
  3. ios：实现插件IOS部分
  4. lib：实现参加Flutter部分

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android：实现插件安卓部分

• //创建FlutterpluginPlugin类实现FlutterPlugin, MethodCallHandler接口
  class FlutterpluginPlugin : FlutterPlugin, MethodCallHandler {
      private lateinit var channel: MethodChannel
  
      override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
        //匹配上和Flutter端相同的MethodChannel
          channel = MethodChannel(flutterPluginBinding.binaryMessenger, "flutterplugin")
          channel.setMethodCallHandler(this)
      }
      //当Flutter端调用方法时
      override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
          if (call.method == "getPlatformVersion") {
              result.success("Android ${android.os.Build.VERSION.RELEASE}")
          } else {
              result.notImplemented()
          }
      }
      override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
          channel.setMethodCallHandler(null)
      }
  }
  

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example：示例项目，将其他3个的实现用于该处

• 导入

• import 'package:flutterplugin/flutterplugin.dart';
  

• 调用

• Flutterplugin.platformVersion
  

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ios：实现插件IOS部分

由于这边的电脑时Window电脑，这个暂时写不了

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lib：实现参加Flutter部分

• 构造MethodChannel对象

  static const MethodChannel _channel =const MethodChannel('channel_name');
  

• 通过上面的MethodChannel对象调用插件提供的方法

   static Future get platformVersion async {
      final String? version = await _channel.invokeMethod('插件实现的方法名字符串');
      return version;
    }
  

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事件监听- android：实现插件安卓部分

• class FlutterpluginPlugin : FlutterPlugin, MethodCallHandler {
      private lateinit var eventChannel: EventChannel
      
      override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
        //匹配和Flutter端相同的EventChannel
          eventChannel = EventChannel(flutterPluginBinding.binaryMessenger, "flutter_event_channel")
          eventChannel.setStreamHandler(streamHandler)
      }
      override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
          if (call.method == "getPlatformVersion") {
              if (eventSink != null) {
                //发送事件
                  eventSink!!.success("这是事件参数，一般使用Map。这里用字符串作示例")
              }
          }
          result.notImplemented()
      }
  
      override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
          channel.setMethodCallHandler(null)
      }
  
      /************ 事件派发到flutter层 *************/
      //eventSink用于发送事件:eventSink!!.success("这是事件参数，一般使用Map。这里用字符串作示例")
      private var eventSink: EventChannel.EventSink? = null
      private val streamHandler = object : EventChannel.StreamHandler {
          override fun onListen(p0: Any?, p1: EventChannel.EventSink?) {
              eventSink = p1
          }
          override fun onCancel(p0: Any?) {
              eventSink = null
          }
      }
  }
  
  

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事件监听- example：示例项目，将其他3个的实现用于该处

• 导入

• import 'package:flutterplugin/flutterplugin.dart';
  

• 触发lib部分构造方法的初始化

  Flutterplugin()
  

• 调用

• Flutterplugin.platformVersion
  

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事件监听- ios：实现插件IOS部分

由于这边的电脑时Window电脑，这个暂时写不了

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事件监听- lib：实现参加Flutter部分

class Flutterplugin {
  //监听注册 对象
  late StreamSubscription subscription;
  Flutterplugin() {
    //注册 监听事件另一端的success和error方法
    subscription = EventChannel("flutter_event_channel")
        .receiveBroadcastStream()
        .listen(handleEvent, onError: errorEvent);
  }
  //success的处理方法
  void handleEvent(dynamic params) {
    final String paramStr = params;
    print(paramStr);
  }
  //error的处理方法
  void errorEvent(dynamic params){}

  static const MethodChannel _channel = const MethodChannel('flutterplugin');

  static Future get platformVersion async {
    final String? version = await _channel.invokeMethod('getPlatformVersion');
    return version;
  }
}