flutter_plugin

PlatformChannels.png

https://github.com/flutter/plugins/tree/master/packages

1、flutter create --template=plugin --platforms=android,ios -i objc -a java hahahaha

• –template=plugin：创建插件包

• –platforms=android,ios：指定平台

• -i objc -a java：指定ios和安卓的语言

• 最后是工程名称

2、插件交互

• 使用

dependencies:
  flutter:
    sdk: flutter

  hahahaha:
    path: ../

    import 'package:hahahaha/hahahaha.dart';

    String platformVersion;
    try {
      platformVersion =
          await Hahahaha.platformVersion ?? 'Unknown platform version';
    } on PlatformException {
      platformVersion = 'Failed to get platform version.';
    }

• MethodChannel（方法通道）上层调底层、底层监听上层

1. 上层中

class Hahahaha {
  static const MethodChannel _channel = MethodChannel('hahahaha');

  static Future<String?> get platformVersion async {
    // 上层调用invokeMethod方法触发底层setMethodCallHandler方法
    final String? version = await _channel.invokeMethod('getPlatformVersion');
    return version;
  }

  static Future<Map<String, String>> sendReq() async {
    final Completer<Map<String, String>> completer = Completer();
    // 上层调用invokeMethod方法触发底层setMethodCallHandler方法
    _channel.invokeMethod('wx_sendReq');
    // 底层调用invokeMethod方法触发上层setMethodCallHandler方法
    _channel.setMethodCallHandler((call) async {
      debugPrint("===授权结果===");
      debugPrint("===method===${call.method}");
      debugPrint("===arguments===${call.arguments}");

      switch (call.method) {
        case "onAuthResponse":
          completer.complete({"state": call.arguments["state"], "code": call.arguments["code"]});
      }
    });
    return completer.future;
  }
}

2. 底层中

/** HahahahaPlugin */
public class HahahahaPlugin implements FlutterPlugin, MethodCallHandler {
  
  @Override
  public void onAttachedToEngine(@NonNull FlutterPluginBinding flutterPluginBinding) {
    channel = new MethodChannel(flutterPluginBinding.getBinaryMessenger(), "hahahaha");
    channel.setMethodCallHandler(this);
  }

  @Override
  public void onMethodCall(@NonNull MethodCall call, @NonNull Result result) {
    if (call.method.equals("getPlatformVersion")) {
      result.success("Android " + android.os.Build.VERSION.RELEASE);
    } else {
      result.notImplemented();
    }
  }

  @Override
  public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
    channel.setMethodCallHandler(null);
  }
}

@implementation HahahahaPlugin
+ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
  FlutterMethodChannel* channel = [FlutterMethodChannel
      methodChannelWithName:@"hahahaha"
            binaryMessenger:[registrar messenger]];
  HahahahaPlugin* instance = [[HahahahaPlugin alloc] init];
  // 上层调用invokeMethod方法触发底层setMethodCallHandler方法
  [registrar addMethodCallDelegate:instance channel:channel];
}

- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
  if ([@"getPlatformVersion" isEqualToString:call.method]) {
    result([@"iOS " stringByAppendingString:[[UIDevice currentDevice] systemVersion]]);
  } else {
    result(FlutterMethodNotImplemented);
  }
}

 // 底层调用invokeMethod方法触发上层setMethodCallHandler事件
 // [channel invokeMethod:@"onAuthResponse" arguments:result];

@end

• EventChannel（事件通道）底层调上层

1.上层中

//创建EventChannel设置监听
final StreamSubscription _eventSubscription = EventChannel('flutter_plugin_event')
          .receiveBroadcastStream()
          .listen((event) {},onError: (error) {
            throw error;
          }
)

2.底层中

  //创建EventChannel名称跟上层监听保持一致，设置setStreamHandler，setStreamHandler会返回一个监听对象eventSink，eventSink来派发事件

  //事件派发对象
  private EventChannel.EventSink eventSink = null;
  //事件派发流
  private EventChannel.StreamHandler streamHandler = new EventChannel.StreamHandler(){
    @Override
    public void onListen(Objct o, EventChannel.EventSink sink){
      eventSink = sink;
    }

    @Override
    public void onCancel(Objct o) {
      eventSink = null;
    }
  };

  private FlutterPlugin(Registrar Registrar, MethodChannel channel) {
    //初始化事件
    EventChannel eventChannel = new EventChannel(Registrar.messenger(),name:"flutter_plugin_event");
    eventChannel.setStreamHandler(streamHandler);
  }
  // 派发事件
  if(eventSink != null) {
    eventSink.success({'event':'demoEvent','value':'value is 10'});
  }

#import "HahahahaPlugin.h"
#import "FlutterPluginEvent.h"


@implementation HahahahaPlugin

FlutterPluginEvent *pluginEvent;


+ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
  FlutterMethodChannel* channel = [FlutterMethodChannel
      methodChannelWithName:@"hahahaha"
            binaryMessenger:[registrar messenger]];
  HahahahaPlugin* instance = [[HahahahaPlugin alloc] init];
  [registrar addMethodCallDelegate:instance channel:channel];


  pluginEvent = [[FlutterPluginEvent alloc] init];
  pluginEvent.eventChannel = [FlutterEventChannel
                                eventChannelWithName:@"flutter_plugin_event"
                                binaryMessenger:[registrar messenger]];
  [pluginEvent.eventChannel setStreamHandler:pluginEvent];
}

- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
  if ([@"getPlatformVersion" isEqualToString:call.method]) {
    result([@"iOS " stringByAppendingString:[[UIDevice currentDevice] systemVersion]]);
  }else if ([@"getNative" isEqualToString:call.method]) {
    result(@"iOS getNative");
  }else if ([@"sayHello" isEqualToString:call.method]) {
    result(@{@"sayHello":call.arguments[@"message"],@"info":@"哈哈info"});
    FlutterEventSink eventSink = pluginEvent.eventSink;
    if(eventSink){
      eventSink(@{@"event" : @"DemoEvent",@"value" : @"ios value is 10",});
    }

  } else {
    result(FlutterMethodNotImplemented);
  }
}

@end

//event dispatcher header file
#import <Flutter/Flutter.h>

@interface FlutterPluginEvent : NSObject<FlutterStreamHandler>
@property (nonatomic, strong) FlutterEventSink eventSink;
@property (nonatomic, strong) FlutterEventChannel* eventChannel;
@end

#import <Foundation/Foundation.h>
#import "FlutterPluginEvent.h"
#import <objc/runtime.h>

@implementation FlutterPluginEvent

@dynamic eventSink;

- (FlutterEventSink)eventSink
{
    return objc_getAssociatedObject(self, _cmd);
}

- (void)setEventSink:(FlutterEventSink)eventSink
{
    objc_setAssociatedObject(self, @selector(eventSink), eventSink, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (FlutterEventChannel *)eventChannel
{
    return objc_getAssociatedObject(self, _cmd);
}

- (void)setEventChannel:(FlutterEventChannel *)eventChannel
{
    objc_setAssociatedObject(self, @selector(eventChannel), eventChannel, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

#pragma mark - FlutterStreamHandler methods

- (FlutterError* _Nullable)onCancelWithArguments:(id _Nullable)arguments {
    self.eventSink = nil;
    return nil;
}

- (FlutterError* _Nullable)onListenWithArguments:(id _Nullable)arguments
                                       eventSink:(nonnull FlutterEventSink)sink {
    self.eventSink = sink;
    return nil;
}

@end

3、发布plugin到pub

• 检查命令
  flutter packages pub publish --dry-run

• 发布命令
  flutter packages pub publish --server=https://pub.dartlang.org

• 配置上网
  export https_proxy=http://127.0.0.1:41091
  export http_proxy=http://127.0.0.1:41091
  set https_proxy=https://127.0.0.1:41091
  set http_proxy=http://127.0.0.1:41091