- 最近忽然想玩玩Flutter，安裝的時候遇到了一些問題，在這裏記錄一下
- 文章來自我的博客，原文鏈接：https://zhj.forever305.cn/2020/02/24/Flutter-Start/
1. Android license status unknown
下載Flutter SDK，配置環境變量之後，在命令行輸入flutter doctor診斷當前環境
PS C:\Users\ZHJ> flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.19564.1000], locale en-US)
[!] Android toolchain - develop for Android devices (Android SDK 29.0.2)
X Android license status unknown.
[√] Android Studio (version 3.2)
X Flutter plugin not installed; this adds Flutter specific functionality.
X Dart plugin not installed; this adds Dart specific functionality.
[!] Connected device
! No devices available
! Doctor found issues in 2 categories.
使用以下命令診斷安卓證書 flutter doctor --android-licenses
PS C:\Users\ZHJ> flutter doctor --android-licenses
A newer version of the Android SDK is required. To update, run:
E:\AndroidStudio\SDK\tools\bin\sdkmanager --update
按照提示，輸入相應命令E:\AndroidStudio\SDK\tools\bin\sdkmanager --update，然而…
PS C:\Users\ZHJ> E:\AndroidStudio\SDK\tools\bin\sdkmanager --update
Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
at com.android.repository.api.SchemaModule$SchemaModuleVersion.<init>(SchemaModule.java:156)
at com.android.repository.api.SchemaModule.<init>(SchemaModule.java:75)
at com.android.sdklib.repository.AndroidSdkHandler.<clinit>(AndroidSdkHandler.java:81)
at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:73)
at com.android.sdklib.tool.sdkmanager.SdkManagerCli.main(SdkManagerCli.java:48)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
... 5 more
上網找了一下原因，大概是因爲我的 JDK 版本太低了，需要去官網下載JDK1.8版本
重新安裝之前，別忘了在控制面板裏把原版JDK卸載掉
重新執行E:\AndroidStudio\SDK\tools\bin\sdkmanager --update
PS C:\Users\ZHJ> E:\AndroidStudio\SDK\tools\bin\sdkmanager --update
Warning: File C:\Users\ZHJ\.android\repositories.cfg could not be loaded.
License intel-android-extra-license: ] 10% Computing updates...
之後接受他的安裝許可
檢查目前狀態
PS C:\Users\ZHJ> flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.19564.1000], locale en-US)
[!] Android toolchain - develop for Android devices (Android SDK 29.0.2)
! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
[√] Android Studio (version 3.2)
X Flutter plugin not installed; this adds Flutter specific functionality.
X Dart plugin not installed; this adds Dart specific functionality.
[!] Connected device
! No devices available
! Doctor found issues in 2 categories.
系統提示有一些證書還未被接受，按照提示重新執行flutter doctor --android-licenses，接受所有條款
PS C:\Users\ZHJ> flutter doctor --android-licenses
Warning: File C:\Users\ZHJ\.android\repositories.cfg could not be loaded.[========= ] 25% F[========= ] 25% Fetch remote repository...
5 of 7 SDK package licenses not accepted. 100% Computing updates...
Review licenses that have not been accepted (y/N)? y
1/5: License android-googletv-license:
---------------------------------------
重新運行自檢程序
PS C:\Users\ZHJ> flutter doctor -v
[√] Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.19564.1000], locale en-US)
• Flutter version 1.0.0 at E:\Flutter\flutter
• Framework revision 5391447fae (1 year, 3 months ago), 2018-11-29 19:41:26 -0800
• Engine revision 7375a0f414
• Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)
[√] Android toolchain - develop for Android devices (Android SDK 29.0.2)
• Android SDK at E:\AndroidStudio\SDK
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-29, build-tools 29.0.2
• ANDROID_HOME = E:\AndroidStudio\SDK
• Java binary at: E:\AndroidStudio\install\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
• All Android licenses accepted.
[√] Android Studio (version 3.2)
• Android Studio at E:\AndroidStudio\install
X Flutter plugin not installed; this adds Flutter specific functionality.
X Dart plugin not installed; this adds Dart specific functionality.
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
[!] Connected device
! No devices available
! Doctor found issues in 1 category.
可以看到，Android toolchain 問題已經解決了
2. Android Studio Flutter plugin not installed
至於這個問題，直接在 Android Stuio 插件安裝界面安裝flutter插件即可
安裝完成後，重啓 Android Studio
如果再啓動界面看到 Start a new Flutter project 說明插件安裝成功
運行自檢程序查看環境狀態
PS C:\Users\ZHJ> flutter doctor -v
[√] Flutter (Channel stable, v1.0.0, on Microsoft Windows [Version 10.0.19564.1000], locale en-US)
• Flutter version 1.0.0 at E:\Flutter\flutter
• Framework revision 5391447fae (1 year, 3 months ago), 2018-11-29 19:41:26 -0800
• Engine revision 7375a0f414
• Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)
[√] Android toolchain - develop for Android devices (Android SDK 29.0.2)
• Android SDK at E:\AndroidStudio\SDK
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-29, build-tools 29.0.2
• ANDROID_HOME = E:\AndroidStudio\SDK
• Java binary at: E:\AndroidStudio\install\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
• All Android licenses accepted.
[√] Android Studio (version 3.2)
• Android Studio at E:\AndroidStudio\install
• Flutter plugin version 31.3.1
• Dart plugin version 181.5656
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
[!] Connected device
! No devices available
! Doctor found issues in 1 category.
OK，現在flutter已經安裝完成了