- 两个网络 - 一个开放式热点网络和一个封闭的专用网络使用WPA。
For example I have two networks:
Which network is automatically joined? Is it random?
There is this file /data/misc/wifi/wpa_supplicant.conf
Each Network you saved is listed there.
When multiple network blocks are listed in this configuration file, the highest priority one is selected for use or, if multiple networks with the same priority are identified, the first one listed in the configuration file is used.
(copy from http://www.freebsd.org/cgi/man.cgi?wpa_supplicant.conf(5), I think Android behaves the same)
There's something called Wi-Fi priority, adjustable for some phones in
Settings - WiFi - Advanced - Wi-Fi priority, and also via some apps and Xposed modules like GravityBox. Android maintains this list of remembered access points and assign priorities to each of them.
I can't find an official definition of how the priorities are (re)assigned (Android Developers only tells me that priority exists), but apparently when you are receiving 2 remembered APs and connected to one of them, then connect to the other, the latter one will receive a boost in priority.
I don't have an idea how "private" networks affect how it works, though.