一、系统环境
flutter最低要求
1，windows7 SP1 64位版本以上，我的系统就是windows 7 sp1 64bit
2，git for windows ，没有安装的需要到这里下载 并安装
3，powershell 5.0及以上，这个据说只有windows10和2016版windows server满足要求
window7 sp1以及自带Powershell，但是版本较低，我的系统中版本居然是2.0
启动：系统左下角-开始-点击搜索框-输入powershell-回车键 在powershell中输入 $PSVersionTable 然后回车，查看其中的PSVersion一行 Windows PowerShell 版权所有 (C) 2009 Microsoft Corporation。保留所有权利。 PS C:Usersgzg> $PSVersionTable Name Value ---- ----- CLRVersion 2.0.50727.8793 BuildVersion 6.1.7601.17514 PSVersion 2.0 WSManStackVersion 2.0 PSCompatibleVersions {1.0, 2.0} SerializationVersion 1.1.0.1 PSRemotingProtocolVersion 2.1 PS C:Usersgzg>
由于PS没有单独的发行包，只能下载WMF5.1的发行包
下载后展开，包含如下两个文件，右键点击Install-WMF5.1.ps1，选择用powershell运行安装，过程不赘述。
4，安装配置好android SDK，并建立一个模拟器
5，Android Studio，如果没有请安装http://www.androiddevtools.cn/。
二、下载安装flutter sdk
1，进入预存放flutter目录的父目录中，从github克隆flutter beta版
git clone -b beta https://github.com/flutter/flutter.git
2，设置环境变量
1）将 *flutterin目录加入到环境变量path中
2）添加ANDROID_HOME环境变量，指向android SDK所在目录
3， 设置国内镜像代理，然后执行flutter doctor
打开dos窗口，设置国内镜像
set PUB_HOSTED_URL=https://pub.flutter-io.cn set FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn
备注：或者也可以直接添加系统变量，以备以后升级安装方便。
4，进行下一步之前，首先关闭杀毒杀木马程序，例如360之类，否则“flutterincacheartifactsengineandroid-arm64-releasewindows-x64gen_snapshot.exe” 会被认成木马，造成运行失败！
我这里的报错信息如下：
K:Androidflutter>flutter doctor Flutter assets will be downloaded from https://storage.flutter-io.cn. Make sure you trust this source! Oops; flutter has exited unexpectedly. Sending crash report to Google.
或者，给目录“flutterin”添加到信任白名单。如果还有问题，看一看flutter目录下的“flutter_##.log”文件查找原因，然后在解决即可。
5，运行flutter设置命令
flutter doctor
flutter会检测flutter SDK安装情况，然后下载dart SDK和其他依赖项目，由于网络问题运行时间较长，期间不免发生失败情况，需要多运行几次。
PS C:Usersgzg> flutter doctor Downloading android-arm-release/windows-x64 tools... Download failed -- attempting retry 1 in 1 second... Download failed -- attempting retry 2 in 2 seconds... Download failed -- attempting retry 3 in 4 seconds... Download failed -- attempting retry 4 in 8 seconds... Download failed -- attempting retry 5 in 16 seconds... Download failed -- attempting retry 6 in 32 seconds... Download failed -- attempting retry 7 in 64 seconds... Download failed -- attempting retry 8 in 64 seconds... 365.2s Downloading android-arm64-profile/windows-x64 tools... 8.2s Downloading android-arm64-release/windows-x64 tools... 7.6s Downloading android-x86 tools... Download failed -- attempting retry 1 in 1 second... Download failed -- attempting retry 2 in 2 seconds... 142.8s Downloading android-x64 tools... 53.4s Downloading android-arm tools... 24.4s Downloading android-arm-profile tools... Oops; flutter has exited unexpectedly. Sending crash report to Google. Failed to send crash report due to a network error: SocketException: OS Error: ä¿¡å·ç¯è¶…时时间已到 , errno = 121, address = clients2.google.com, port = 60527 Crash report written to C:Usersgzgflutter_03.log; please let us know at https://github.com/flutter/flutter/issues. PS C:Usersgzg> flutter doctor Downloading android-arm-profile tools... Download failed -- attempting retry 1 in 1 second... Download failed -- attempting retry 2 in 2 seconds... Download failed -- attempting retry 3 in 4 seconds... Download failed -- attempting retry 4 in 8 seconds... Download failed -- attempting retry 5 in 16 seconds... Download failed -- attempting retry 6 in 32 seconds... 254.5s Downloading android-arm-release tools... Download failed -- attempting retry 1 in 1 second... 61.0s Downloading android-arm64 tools... 27.6s Downloading android-arm64-profile tools... Download failed -- attempting retry 1 in 1 second... 71.0s Downloading android-arm64-release tools... Download failed -- attempting retry 1 in 1 second... Download failed -- attempting retry 2 in 2 seconds... Download failed -- attempting retry 3 in 4 seconds... Download failed -- attempting retry 4 in 8 seconds... Download failed -- attempting retry 5 in 16 seconds...
6，最后，flutter doctor命令会给出环境检测结果，如果有些项目有问题，则按照其中说明修正，例如，我这里有两项有问题：
Doctor summary (to see all details, run flutter doctor -v): [√] Flutter (Channel unknown, v0.0.0-unknown, on Microsoft Windows [Version 6.1.7601], locale zh-CN) [!] Android toolchain - develop for Android devices (Android SDK 28.0.3) ! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses [√] Android Studio (version 3.2) [√] IntelliJ IDEA Community Edition (version 2018.2) [!] Connected device ! No devices available ! Doctor found issues in 2 categories.
第二项问题依照蓝色提示操作即可解决。最后一项虚拟机，建立一个虚拟机并启动，再次运行检测，没问题了！
C:Usersgzg>flutter doctor Doctor summary (to see all details, run flutter doctor -v): [√] Flutter (Channel unknown, v0.0.0-unknown, on Microsoft Windows [Version 6.1.7601], locale zh-CN) [√] Android toolchain - develop for Android devices (Android SDK 28.0.3) [√] Android Studio (version 3.2) [√] IntelliJ IDEA Community Edition (version 2018.2) [√] Connected device (1 available) • No issues found!
三、开始flutter之旅
在android studio中建立flutter项目
菜单“File--New--New Flutter Project...”，第一步选择“Flutter Application”，第二部输入项目名称，注意一定要选中下面的选项“create project offline”，否则在我的网络环境下就进行不下去了。
