指定插件所支援的平台

插件可以通過向pubspec.yaml中的platformsmap 添加keys 來指定其支援的平台

例如，以下是hello插件的flutter:map：

hello插件僅支援 iOS 和 Android，在platformsmap 添加keys，指定其支援的平台

flutter:
  plugin:
    platforms:
      android:
        package: com.example.hello
        pluginClass: HelloPlugin
      ios:
        pluginClass: HelloPlugin

environment:
  sdk: ">=2.1.0 <3.0.0"
  # Flutter versions prior to 1.12 did not support the
  # flutter.plugin.platforms map.
  flutter: ">=1.12.0"

當為更多平台添加插件實現時，應相應地更新platformsmap

flutter:
  plugin:
    platforms:
      android:
        package: com.example.hello
        pluginClass: HelloPlugin
      ios:
        pluginClass: HelloPlugin
      macos:
        pluginClass: HelloPlugin
      web:
        pluginClass: HelloPlugin
        fileName: hello_web.dart

environment:
  sdk: ">=2.1.0 <3.0.0"
  # Flutter versions prior to 1.12 did not support the
  # flutter.plugin.platforms map.
  flutter: ">=1.12.0"