1. example中main.dart布局
   

2. 注意:FlutterPluginOne是在创建插件时根据名字来进行创建的,如下图:

   

   具体内容如下:

class FlutterPluginOne {
  // 这里的flutter_plugin_one字符串没有特殊要求,只需要和FlutterPluginOnePlugin.kt中的设置一样即可,即第4步
  static const MethodChannel _channel =
      const MethodChannel(‘flutter_plugin_one‘);

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

  // 显示Toast
  static Future<void> showToast() async {
    await _channel.invokeMethod("showToast");
  }
  // 通过get
  static Future<void> get showToastByGet async {
    await _channel.invokeMethod("showToast");
  }
  // 接受参数
  static Future<void> showToastByMessage({String? message}) async {
    Map param = Map<String,String>();
    param["message"] = message ?? "showToastByMessage";
    await _channel.invokeMapMethod("showToastByMessage",param);
  }
}

3. 插件项目下的android目录下:

   

4. FlutterPluginOnePlugin.kt中的内容如下:

   /** FlutterPluginOnePlugin */
   class FlutterPluginOnePlugin() : FlutterPlugin, MethodCallHandler {
   
       private lateinit var context: Context
   
       /// The MethodChannel that will the communication between Flutter and native Android
       ///
       /// This local reference serves to register the plugin with the Flutter Engine and unregister it
       /// when the Flutter Engine is detached from the Activity
       private lateinit var methodChannel: MethodChannel
       private lateinit var eventChannel: EventChannel
   
   
       override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
           methodChannel = MethodChannel(flutterPluginBinding.binaryMessenger, "flutter_plugin_one")
           methodChannel.setMethodCallHandler(this)
           context = flutterPluginBinding.applicationContext
       }
   
       override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
           if (call.method == "getPlatformVersion") {
               result.success("Android ${android.os.Build.VERSION.RELEASE}")
           } else if (call.method == "showToast") {
               Toast.makeText(context, "来自Android SDK中的Toast", Toast.LENGTH_SHORT)
                   .show()
           } else if (call.method == "showToastByMessage") {
               val arguments = call.arguments as Map<*, *>
               Toast.makeText(context, arguments["message"] as String, Toast.LENGTH_SHORT)
                   .show()
           } else {
               result.notImplemented()
           }
       }
   
       override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
           methodChannel.setMethodCallHandler(null)
       }
   }
   

5. 当我们点击+按钮时,就会弹出“来自Android SDK中的Toast”内容。

   

Flutter插件开发---》调用Android原生Toast