参考网页：
android studio 学习入门篇
https://blog.csdn.net/myosotis5/article/details/79208707
Android studio安装与配置
https://www.cnblogs.com/xiadewang/p/7820377.html
1 下载 android studio
http://www.android-studio.org/
https://developer.android.google.cn/studio/ （官方）
下载下来的为：android-studio-ide-173.4907809-windows.exe
大小为790M字节，安装包不带SDK
2 安装 android studio 3.1.4
D:\Program Files\Android\Android Studio
3 启动 android
Preparing "Install Android SDK Platform-Tools (revision: 28.0.0)".
Downloading https://dl.google.com/android/repository/platform-tools_r28.0.0-windows.zip
"Install Android SDK Platform-Tools (revision: 28.0.0)" ready.
Installing Android SDK Platform-Tools in C:\Users\AAA\AppData\Local\Android\Sdk\platform-tools
"Install Android SDK Platform-Tools (revision: 28.0.0)" complete.
"Install Android SDK Platform-Tools (revision: 28.0.0)" finished.
Preparing "Install Android Support Repository (revision: 47.0.0)".
Downloading https://dl.google.com/android/repository/android_m2repository_r47.zip
"Install Android Support Repository (revision: 47.0.0)" ready.
Installing Android Support Repository in C:\Users\AAA\AppData\Local\Android\Sdk\extras\android\m2repository
"Install Android Support Repository (revision: 47.0.0)" complete.
"Install Android Support Repository (revision: 47.0.0)" finished.
Preparing "Install Android SDK Tools (revision: 26.1.1)".
Downloading https://dl.google.com/android/repository/sdk-tools-windows-4333796.zip
"Install Android SDK Tools (revision: 26.1.1)" ready.
Installing Android SDK Tools in C:\Users\AAA\AppData\Local\Android\Sdk\tools
"Install Android SDK Tools (revision: 26.1.1)" complete.
"Install Android SDK Tools (revision: 26.1.1)" finished.
Preparing "Install Sources for Android 28 (revision: 1)".
Downloading https://dl.google.com/android/repository/sources-28_r01.zip
"Install Sources for Android 28 (revision: 1)" ready.
Installing Sources for Android 28 in C:\Users\AAA\AppData\Local\Android\Sdk\sources\android-28
"Install Sources for Android 28 (revision: 1)" complete.
"Install Sources for Android 28 (revision: 1)" finished.
Preparing "Install Android SDK Platform 28 (revision: 6)".
Downloading https://dl.google.com/android/repository/platform-28_r06.zip
"Install Android SDK Platform 28 (revision: 6)" ready.
Installing Android SDK Platform 28 in C:\Users\AAA\AppData\Local\Android\Sdk\platforms\android-28
"Install Android SDK Platform 28 (revision: 6)" complete.
"Install Android SDK Platform 28 (revision: 6)" finished.
Preparing "Install SDK Patch Applier v4 (revision: 1)".
Downloading https://dl.google.com/android/repository/3534162-studio.sdk-patcher.zip.bak
"Install SDK Patch Applier v4 (revision: 1)" ready.
Installing SDK Patch Applier v4 in C:\Users\AAA\AppData\Local\Android\Sdk\patcher\v4
"Install SDK Patch Applier v4 (revision: 1)" complete.
"Install SDK Patch Applier v4 (revision: 1)" finished.
Preparing "Install Android Emulator (revision: 27.3.9)".
Downloading https://dl.google.com/android/repository/emulator-windows-4899998.zip
"Install Android Emulator (revision: 27.3.9)" ready.
Installing Android Emulator in C:\Users\AAA\AppData\Local\Android\Sdk\emulator
"Install Android Emulator (revision: 27.3.9)" complete.
"Install Android Emulator (revision: 27.3.9)" finished.
Preparing "Install Google Repository (revision: 58)".
Downloading https://dl.google.com/android/repository/google_m2repository_gms_v11_3_rc05_wear_2_0_5.zip
"Install Google Repository (revision: 58)" ready.
Installing Google Repository in C:\Users\AAA\AppData\Local\Android\Sdk\extras\google\m2repository
"Install Google Repository (revision: 58)" complete.
"Install Google Repository (revision: 58)" finished.
Preparing "Install Intel x86 Emulator Accelerator (HAXM installer) (revision: 7.2.0)".
Downloading https://dl.google.com/android/repository/extras/intel/haxm-windows_v7_2_0.zip
"Install Intel x86 Emulator Accelerator (HAXM installer) (revision: 7.2.0)" ready.
Installing Intel x86 Emulator Accelerator (HAXM installer) in C:\Users\AAA\AppData\Local\Android\Sdk\extras\intel\Hardware_Accelerated_Execution_Manager
"Install Intel x86 Emulator Accelerator (HAXM installer) (revision: 7.2.0)" complete.
"Install Intel x86 Emulator Accelerator (HAXM installer) (revision: 7.2.0)" finished.
Preparing "Install Android SDK Build-Tools 28.0.2 (revision: 28.0.2)".
Downloading https://dl.google.com/android/repository/build-tools_r28.0.2-windows.zip
"Install Android SDK Build-Tools 28.0.2 (revision: 28.0.2)" ready.
Installing Android SDK Build-Tools 28.0.2 in C:\Users\AAA\AppData\Local\Android\Sdk\build-tools\28.0.2
"Install Android SDK Build-Tools 28.0.2 (revision: 28.0.2)" complete.
"Install Android SDK Build-Tools 28.0.2 (revision: 28.0.2)" finished.
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\build-tools\28.0.2\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\emulator\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\extras\android\m2repository\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\extras\google\m2repository\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\extras\intel\Hardware_Accelerated_Execution_Manager\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\patcher\v4\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\platform-tools\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\platforms\android-28\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\sources\android-28\package.xml
Parsing C:\Users\AAA\AppData\Local\Android\Sdk\tools\package.xml
Android SDK is up to date.
Running Intel® HAXM installer
Intel HAXM installed successfully!
AAA
To install:
- Solver for ConstraintLayout 1.0.2 (extras;m2repository;com;android;support;constraint;constraint-layout-solver;1.0.2)
- ConstraintLayout for Android 1.0.2 (extras;m2repository;com;android;support;constraint;constraint-layout;1.0.2)
Preparing "Install Solver for ConstraintLayout 1.0.2 (revision: 1)".
Downloading file:/D:/Program%20Files/Android/Android%20Studio/plugins/sdk-updates/offline-repo/com.android.support.constraint-constraint-layout-solver-1.0.2.zip
"Install Solver for ConstraintLayout 1.0.2 (revision: 1)" ready.
Preparing "Install ConstraintLayout for Android 1.0.2 (revision: 1)".
Downloading file:/D:/Program%20Files/Android/Android%20Studio/plugins/sdk-updates/offline-repo/com.android.support.constraint-constraint-layout-1.0.2.zip
"Install ConstraintLayout for Android 1.0.2 (revision: 1)" ready.
Installing Solver for ConstraintLayout 1.0.2 in C:\Users\AAA\AppData\Local\Android\Sdk\extras\m2repository\com\android\support\constraint\constraint-layout-solver\1.0.2
"Install Solver for ConstraintLayout 1.0.2 (revision: 1)" complete.
Writing Maven metadata to C:\Users\AAA\AppData\Local\Android\Sdk\extras\m2repository\com\android\support\constraint\constraint-layout-solver\maven-metadata.xml
"Install Solver for ConstraintLayout 1.0.2 (revision: 1)" finished.
Installing ConstraintLayout for Android 1.0.2 in C:\Users\AAA\AppData\Local\Android\Sdk\extras\m2repository\com\android\support\constraint\constraint-layout\1.0.2
"Install ConstraintLayout for Android 1.0.2 (revision: 1)" complete.
Writing Maven metadata to C:\Users\AAA\AppData\Local\Android\Sdk\extras\m2repository\com\android\support\constraint\constraint-layout\maven-metadata.xml
"Install ConstraintLayout for Android 1.0.2 (revision: 1)" finished.C:\Users\AAA.gradle\wrapper\dists\gradle-4.4-all\9br9xq1tocpiv8o6njlyu5op1\gradle-4.4-all.zip