1.运行SDK Manager。

2.Android SDK Manager"=>"Tools"=>"Options...",勾选"Others"中的"Force https://...sources to be fetched using http://..."选项。如下图所示：

下载SDK总是会出现如下错误：

  Failed to fetch URL http://dl-ssl.google.com/android/repository/addons_list-1.xml.

解决方法就是修改C:\Windows\System32\drivers\etc\hosts文件。添加一行：

这里需要注意的是hosts文件是只读的，我们没有权限修改，需要我们将hosts文件复制到桌面或者其他地方，然后修改，代码如下：

# Copyright (c) 1993-2009 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a ‘#‘ symbol.
#
# For example:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
//增加这一句
74.125.237.1 dl-ssl.google.com

SDK其他更新通道

#==== Android SDK更新通道203.208.46.146 dl.google.com203.208.46.146 dl-ssl.google.com#====

或者，效果同上，添加其中之一即可！

#==== Android SDK更新通道74.125.237.1 dl.google.com74.125.237.1 dl-ssl.google.com#====

Android SDK Manager下载失败后 更新列表的正确设置