添加语言切换

lib/generated/intl/messages_all.dart

@@ -0,0 +1,72 @@
+// DO NOT EDIT. This is code generated via package:intl/generate_localized.dart
+// This is a library that looks up messages for specific locales by
+// delegating to the appropriate library.
+
+// Ignore issues from commonly used lints in this file.
+// ignore_for_file:implementation_imports, file_names, unnecessary_new
+// ignore_for_file:unnecessary_brace_in_string_interps, directives_ordering
+// ignore_for_file:argument_type_not_assignable, invalid_assignment
+// ignore_for_file:prefer_single_quotes, prefer_generic_function_type_aliases
+// ignore_for_file:comment_references
+
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:intl/intl.dart';
+import 'package:intl/message_lookup_by_library.dart';
+import 'package:intl/src/intl_helpers.dart';
+
+import 'messages_en.dart' as messages_en;
+import 'messages_zh.dart' as messages_zh;
+
+typedef Future<dynamic> LibraryLoader();
+Map<String, LibraryLoader> _deferredLibraries = {
+  'en': () => new SynchronousFuture(null),
+  'zh': () => new SynchronousFuture(null),
+};
+
+MessageLookupByLibrary? _findExact(String localeName) {
+  switch (localeName) {
+    case 'en':
+      return messages_en.messages;
+    case 'zh':
+      return messages_zh.messages;
+    default:
+      return null;
+  }
+}
+
+/// User programs should call this before using [localeName] for messages.
+Future<bool> initializeMessages(String localeName) {
+  var availableLocale = Intl.verifiedLocale(
+    localeName,
+    (locale) => _deferredLibraries[locale] != null,
+    onFailure: (_) => null,
+  );
+  if (availableLocale == null) {
+    return new SynchronousFuture(false);
+  }
+  var lib = _deferredLibraries[availableLocale];
+  lib == null ? new SynchronousFuture(false) : lib();
+  initializeInternalMessageLookup(() => new CompositeMessageLookup());
+  messageLookup.addLocale(availableLocale, _findGeneratedMessagesFor);
+  return new SynchronousFuture(true);
+}
+
+bool _messagesExistFor(String locale) {
+  try {
+    return _findExact(locale) != null;
+  } catch (e) {
+    return false;
+  }
+}
+
+MessageLookupByLibrary? _findGeneratedMessagesFor(String locale) {
+  var actualLocale = Intl.verifiedLocale(
+    locale,
+    _messagesExistFor,
+    onFailure: (_) => null,
+  );
+  if (actualLocale == null) return null;
+  return _findExact(actualLocale);
+}