Dart：尝试运行 .dart 文件时未找到 UI

Question

我试图在 Flutter 项目中运行我的 .dart 文件，以了解 SQlite 数据库如何在 Flutter 应用程序中工作。所以我正在执行我的 .dart 文件然后出现此错误

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C:\\Users\\ChangNoi\\Desktop\\GitHub\\project_fight_2\\lib\\backend>dart database.dart\ndatabase.dart: Warning: Interpreting this as package URI,'package:projectfight2/backend/database.dart'.\n\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/binary_messenger.dart:7:8: Error: Notfound: 'dart:ui'\nimport 'dart:ui' as ui;\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/binding.dart:7:8: Error: Not found: 'dart:ui'\nimport 'dart:ui' as ui;\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/font_loader.dart:7:8: Error: Not found: 'dart:ui'\nimport 'dart:ui';\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/platform_messages.dart:7:8: Error: Not found: 'dart:ui'\nimport 'dart:ui' as ui;\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/platform_views.dart:7:8: Error: Not found: 'dart:ui'\nimport 'dart:ui';\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/raw_keyboard.dart:7:8: Error: Not found: 'dart:ui'\nimport 'dart:ui';\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/system_channels.dart:5:8: Error: Not found: 'dart:ui'\nimport 'dart:ui';\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/system_chrome.dart:6:8: Error: Not found: 'dart:ui'\nimport 'dart:ui';\n   ^\n/C:/Program%20Files/Flutter/packages/flutter/lib/src/services/system_chrome.dart:12:1: Error: Not found: 'dart:ui'\nexport 'dart:ui' show Brightness;\n

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我不确定为什么在多次重新启动 IDE 并调用 flutter pub get 后仍然发生此错误

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这是我的颤振医生完整结果

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[\xe2\x88\x9a] Flutter (Channel master, 1.19.0-2.0.pre.143, on Microsoft Windows [Version 10.0.18362.836], locale en-US)\n\xe2\x80\xa2 Flutter version 1.19.0-2.0.pre.143 at C:\\Program Files\\Flutter\n\xe2\x80\xa2 Framework revision 9d58a87066 (5 hours ago), 2020-05-22 22:37:01 -0700\n\xe2\x80\xa2 Engine revision 9ce1e5c5c7\n\xe2\x80\xa2 Dart version 2.9.0 (build 2.9.0-10.0.dev 7706afbcf5)\n\n\n[\xe2\x88\x9a] Android toolchain - develop for Android devices (Android SDK version 29.0.3)\n\xe2\x80\xa2 Android SDK at C:\\Users\\ChangNoi\\AppData\\Local\\Android\\sdk\n\xe2\x80\xa2 Platform android-29, build-tools 29.0.3\n\xe2\x80\xa2 Java binary at: C:\\Program Files\\Android\\Android Studio\\jre\\bin\\java\n\xe2\x80\xa2 Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)\n\xe2\x80\xa2 All Android licenses accepted.\n\n[\xe2\x88\x9a] Android Studio (version 3.6)\n\xe2\x80\xa2 Android Studio at C:\\Program Files\\Android\\Android Studio\n\xe2\x80\xa2 Flutter plugin version 45.1.1\n\xe2\x80\xa2 Dart plugin version 192.8052\n\xe2\x80\xa2 Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)\n\n[\xe2\x88\x9a] VS Code, 64-bit edition (version 1.45.1)\n\xe2\x80\xa2 VS Code at C:\\Program Files\\Microsoft VS Code\n\xe2\x80\xa2 Flutter extension version 3.10.2\n\n[\xe2\x88\x9a] Connected device (1 available)\n\xe2\x80\xa2 Android SDK built for x86 \xe2\x80\xa2 emulator-5554 \xe2\x80\xa2 android-x86 \xe2\x80\xa2 Android 7.1.1 (API 25) (emulator)\n

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Answer 1

运行应用程序时，你会发现 2 个 main.dart 选择Flutter旁边有 图标的那个。

从这里得到参考