如果网络不稳定，则VS的安卓仿真器很容易下载失败，如下
Downloaded file '<USER_HOME>\AppData\Local\Temp\xamarin-android-sdk\x86_64-35_r08.zip' not found for Android SDK archive 'https://dl.google.com/android/repository/sys-img/google_apis_playstore/x86_64-35_r08.zip'
正在下载 Google Play Intel x86_64 Atom System Image v8 5%
正在下载 Google Play Intel x86_64 Atom System Image v8 10%
正在下载 Google Play Intel x86_64 Atom System Image v8 15%
正在下载 Google Play Intel x86_64 Atom System Image v8 20%
正在下载 Google Play Intel x86_64 Atom System Image v8 25%
超时: 请检查你的 Internet 连接
System.TimeoutException: 操作已超时。
刷新 android sdk 信息，因为已安装 Android sdk 组件
正在下载 Google Play Intel x86_64 Atom System Image v8 CompletedCompletedCompletedCompleted
[RunLongOperation] exception
操作失败:
这句话的信息量比较大
Downloaded file '<USER_HOME>\AppData\Local\Temp\xamarin-android-sdk\x86_64-35_r08.zip' not found for Android SDK archive 'https://dl.google.com/android/repository/sys-img/google_apis_playstore/x86_64-35_r08.zip'
一来告诉我们把安装包放在什么位置，二来告诉我们在哪里下载安装包
我们只需要把这个地址复制进浏览器，就能自动开始下载，推荐科学上网
https://dl.google.com/android/repository/sys-img/google_apis_playstore/x86_64-35_r08.zip
将下载好的软件放入指定路径后，点击重试即可
正在应用 Android SDK 更改 Started
正在安装 Android SDK 组件 Started
正在安装 Google Play Intel x86_64 Atom System Image v8 Started
正在下载 Google Play Intel x86_64 Atom System Image v8 Started
正在下载 Google Play Intel x86_64 Atom System Image v8 Completed
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] Started
Installing Android SDK component: Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] (system-images;android-35;google_apis_playstore;x86_64)
Unzipping file '<USER_HOME>\AppData\Local\Temp\xamarin-android-sdk\x86_64-35_r08.zip' to directory '<USER_HOME>\AppData\Local\Temp\61a9a077'
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 9%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 18%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 27%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 36%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 45%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 50%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 59%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 68%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 77%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] 86%
Archive unzipped to '<USER_HOME>\AppData\Local\Temp\61a9a077\x86_64'
Moving Android component to its destination path.
正在安装组件 100%
Installing Google Play Intel x86_64 Atom System Image r8 [System Image: X86_64 API 35 (Google Inc.)] CompletedCompleted后面还要下载东西
正在安装 Android Emulator v35.1.20 Started
正在下载 Android Emulator v35.1.20 Started
Downloaded file '<USER_HOME>\AppData\Local\Temp\xamarin-android-sdk\emulator-windows_x64-12234392.zip' not found for Android SDK archive 'https://dl.google.com/android/repository/emulator-windows_x64-12234392.zip'
刷新 android sdk 信息，因为已安装 Android sdk 组件
正在下载 Android Emulator v35.1.20 Completed
如法炮制即可
Unzipping file '<USER_HOME>\AppData\Local\Temp\xamarin-android-sdk\emulator-windows_x64-12234392.zip' to directory '<USER_HOME>\AppData\Local\Temp\692234e8'
Installing Android Emulator r35.1.20 9%
Installing Android Emulator r35.1.20 18%
Installing Android Emulator r35.1.20 27%
Installing Android Emulator r35.1.20 32%
Installing Android Emulator r35.1.20 41%
Installing Android Emulator r35.1.20 46%
Installing Android Emulator r35.1.20 55%
Installing Android Emulator r35.1.20 64%
Installing Android Emulator r35.1.20 73%
Installing Android Emulator r35.1.20 78%
Installing Android Emulator r35.1.20 87%
Archive unzipped to '<USER_HOME>\AppData\Local\Temp\692234e8\emulator'
Moving Android component to its destination path.
正在安装组件 100%
Installing Android Emulator r35.1.20 CompletedCompleted
刷新 android sdk 信息，因为已安装 Android sdk 组件CompletedCompleted
安装完成胜利结算画面
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