小编Fat*_*Crg的帖子

如何从长文件中获取前几个词（摘录）String。我有一个大故事类型字符串，需要在屏幕上显示前 5-10 个单词，其余的要在下一个屏幕上显示。那么有没有办法做到这一点。我搜索了很多，但无法解决问题。例如：获取我们使用的第一个字母

String sentence = "My single Sentence";
sentence[0] //M

同样，我需要得到一些词。例如：

String bigSentence ='''
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book
''';
//code to get the excerpt()

//predicted output=> Lorem Ipsum is simply dummy text...

我在我的 flutter 应用程序中使用 Firebase Firestore。模式下一切正常debug。但是，在release模式下，我收到以下错误。\n我看到了类似的问题，但它没有解决我的问题。

[ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: [cloud_firestore/unavailable] \nThe service is currently unavailable. This is a most likely a transient condition and may be corrected by retrying with a backoff.\nE/flutter ( 3646): #0      MethodChannelDocumentReference.get \n(package:cloud_firestore_platform_interface/src/method_channel/method_channel_document_reference.dart:80)\nE/flutter ( 3646): <asynchronous suspension>\nE/flutter ( 3646): #1      DocumentReference.get (package:cloud_firestore/src/document_reference.dart:58)\nE/flutter ( 3646): <asynchronous suspension>\n

$ flutter doctor\n>> Flutter (Channel stable, 2.2.3, Version 10.0.21996.1)\n>> \xe2\x80\xa2 No issues found!\n

我试过

\n
• 添加INTERNET权限。
\n
• 更改 Gradle 版本。
\n …