在Flutter 1.7.3出现编警告

[SnowLittleStone]

在ios平台运行flutter run，出现以下的警告错误
/Users/yfb/flutter/.pub-cache/hosted/pub.flutter-io.cn/flutter_filereader-2.1.0/ios/Classes/SwiftFlutterFileReaderPlugin.swift:25:25: warning:
'substring(from:)' is deprecated: Please use String slicing subscript with a 'partial range from' operator.
str = filePath!.substring(from: String.Index.init(encodedOffset: (i.encodedOffset + 1)))
^
/Users/yfb/flutter/.pub-cache/hosted/pub.flutter-io.cn/flutter_filereader-2.1.0/ios/Classes/SwiftFlutterFileReaderPlugin.swift:25:54: warning:
'init(encodedOffset:)' is deprecated: encodedOffset has been deprecated as most common usage is incorrect. Use String.Index(utf16Offset:in:) to achieve
the same behavior.
str = filePath!.substring(from: String.Index.init(encodedOffset: (i.encodedOffset + 1)))
^
/Users/yfb/flutter/.pub-cache/hosted/pub.flutter-io.cn/flutter_filereader-2.1.0/ios/Classes/SwiftFlutterFileReaderPlugin.swift:25:77: warning:
'encodedOffset' is deprecated: encodedOffset has been deprecated as most common usage is incorrect. Use utf16Offset(in:) to achieve the same behavior.
str = filePath!.substring(from: String.Index.init(encodedOffset: (i.encodedOffset + 1)))