Can we program to automatically join the WiFi with the most strongest signal by no manual selection?

I am making a iphone program, I wish that:

1. it can sense and display the current signals of wifi, with strength, - as I checked, this cannot be done by official SDK, but there were some private library that can handle.

2. i wish it can always automatically join the best wifi with the most highest strength ( assume that all wifi APs have no password, and all are not remembered into the used-list inside iphone), which is something like "seamless handover"...

I just guess that, there should be some APIs to let the system jo开发者_开发知识库in one designated wifi signal from the list, and wish someone could help me. I would like to appreciate a lot : )

Thanks a lot!

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Based on this bug report and this SO question, I'm guessing there's no supported way to detect the Wifi's signal strength at the moment.

According to the WiFinder author's blog he used methods from the private Apple80211.framework. (The framework mentioned in the above linked SO question.) Apparently Apple will no longer allow these private API calls in apps, which is preventing him from updating WiFinder.

But, if you want to use them anyway, some kind folks have posted a list of discovered Apple80211 functions to google code.

It looks like Apple80211GetInfoCopy might do the trick.