手动下载SDK tools，Build Tools，Platforms……

举个栗子，
手动下载sdk tools r25.2.5 mac版本：
https://dl.google.com/android/repository/tools_r25.2.5-macosx.zip
手动下载ndk r10e linux版本：
https://dl.google.com/android/repository/android-ndk-r10e-linux-x86_64.zip

Manual download

As not every package (especially the old ones) is listed when you do android sdk list, you can also download things manually. You can manually open the XML file that is shown when during android sdk list - https://dl.google.com/android/repository/repository-11.xml

You can find there links to various types of things to download, e.g:

ADT
http://dl.google.com/android/ADT-XX.0.0.zip

SDK Tools
http://dl.google.com/android/repository/tools_rXX-linux_x86.zip
http://dl.google.com/android/repository/tools_rXX-windows.zip
http://dl.google.com/android/repository/tools_rXX-macosx.zip

Platform Tools
http://dl.google.com/android/repository/platform-tools_rXX-linux_x86.zip
http://dl.google.com/android/repository/platform-tools_rXX-windows.zip
http://dl.google.com/android/repository/platform-tools_rXX-macosx.zip

Build Tools
http://dl.google.com/android/repository/build-tools_rXX-linux.zip
http://dl.google.com/android/repository/build-tools_rXX-windows.zip
http://dl.google.com/android/repository/build-tools_rXX-macosx.zip

Platforms
http://dl.google.com/android/repository/android-XX.zip