增加null-safety

lib/flutter_system.dart

@@ -4,8 +4,7 @@ import 'dart:io';
 import 'package:flutter/services.dart';
 
 class FlutterSystem {
-  static const MethodChannel _channel =
-      const MethodChannel('flutter_system');
+  static const MethodChannel _channel = const MethodChannel('flutter_system');
 
   static void openAlarm() {
     if(Platform.isIOS){

pubspec.lock

@@ -7,49 +7,49 @@ packages:
       name: async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.8.1"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.3.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -66,21 +66,21 @@ packages:
       name: matcher
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.7.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -92,56 +92,56 @@ packages:
       name: source_span
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.4.2"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
+  dart: ">=2.12.0 <3.0.0"
   flutter: ">=1.20.0"

pubspec.yaml

 name: flutter_system
 description: A new flutter plugin project.
-version: 0.0.1
-author:
+version: 1.0.0
 homepage:
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
   flutter: ">=1.20.0"
 
 dependencies:
@@ -16,15 +15,7 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
 
-# For information on the generic Dart part of this file, see the
-# following page: https://dart.dev/tools/pub/pubspec
-
-# The following section is specific to Flutter.
 flutter:
-  # This section identifies this Flutter project as a plugin project.
-  # The 'pluginClass' and Android 'package' identifiers should not ordinarily
-  # be modified. They are used by the tooling to maintain consistency when
-  # adding or updating assets for this project.
   plugin:
     platforms:
       android:
@@ -32,34 +23,3 @@ flutter:
         pluginClass: FlutterSystemPlugin
       ios:
         pluginClass: FlutterSystemPlugin
\ No newline at end of file
-
-  # To add assets to your plugin package, add an assets section, like this:
-  # assets:
-  #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
-  #
-  # For details regarding assets in packages, see
-  # https://flutter.dev/assets-and-images/#from-packages
-  #
-  # An image asset can refer to one or more resolution-specific "variants", see
-  # https://flutter.dev/assets-and-images/#resolution-aware.
-
-  # To add custom fonts to your plugin package, add a fonts section here,
-  # in this "flutter" section. Each entry in this list should have a
-  # "family" key with the font family name, and a "fonts" key with a
-  # list giving the asset and other descriptors for the font. For
-  # example:
-  # fonts:
-  #   - family: Schyler
-  #     fonts:
-  #       - asset: fonts/Schyler-Regular.ttf
-  #       - asset: fonts/Schyler-Italic.ttf
-  #         style: italic
-  #   - family: Trajan Pro
-  #     fonts:
-  #       - asset: fonts/TrajanPro.ttf
-  #       - asset: fonts/TrajanPro_Bold.ttf
-  #         weight: 700
-  #
-  # For details regarding fonts in packages, see
-  # https://flutter.dev/custom-fonts/#from-packages