搜索许多网站后即可解决此问题。我不能，当我尝试运行应用程序时，出现此错误：
Error: 'ActionFactory' isn't a type.
Map<LocalKey, ActionFactory> actions,
^^^^^^^^^^^^^
颤抖的医生输出：
[√] Flutter (Channel stable, 1.20.1, on Microsoft Windows [Version 6.3.9600], locale en-US)
• Flutter version 1.20.1 at F:\software\flutter
• Framework revision 2ae34518b8 (7 days ago), 2020-08-05 19:53:19 -0700
• Engine revision c8e3b94853
• Dart version 2.9.0
[!] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
• Android SDK at F:\software\sdk
• Platform android-30, build-tools 30.0.0
• ANDROID_HOME = F:\software\sdk
• Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
[√] Android Studio (version 4.0)
• Android Studio at C:\Program Files\Android\Android Studio
• Flutter plugin version 48.1.2
• Dart plugin version 193.7361
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
[√] Connected device (1 available)
• WAS LX1A (mobile) • 2XJDU17C14006203 • android-arm64 • Android 8.0.0 (API 26)
! Doctor found issues in 1 category.