【flutter填坑】The non-abstract clas

报错日志大概如下：

Error: The non-abstract class 'ExtendedTextSelectionState' is missing implementations for these members: - TextSelectionDelegate.copySelection - TextSelectionDelegate.cutSelection - TextSelectionDelegate.pasteText - TextSelectionDelegate.selectAll Try to either - provide an implementation, - inherit an implementation from a superclass or mixin, - mark the class as abstract, or - provide a 'noSuchMethod' implementation.

这个问题出现的原因，大概率是你升级了flutter版本后导致的，extended_text的插件版本和flutter版本不匹配。
解决方案是升级extended_text插件版本

extended_text: ^9.0.0

除此之外，建议在flutter upgrade后，在项目的控制台中使用

flutter pub upgrade

以此可以避免出现pub相关问题