Android Studio 2.1.1: “no usb devices or running emulators detected”

问题

Suddenly my Android Studio stopped detecting all my devices, none of them is working. It happen from one execution to another. I've changed a few lines of code (1 min maybe?), hit run (instant run) and then I missed all my devices.

I'm using a Mac and as devices: Nexus 5x, Galaxy s6 and Oneplus One. What can be happening? I've checked previous questions here and tried all this:

Run configurations: no matter if I chose usb device or show the window, it does not work.
Tools > Android > Enable ADB integration: didn't help
Command line adb devices does not detect any either.
I've revoked and granted again USB authorizations. Still not working.
I've tried other apps I have, none work.
Restarted phones
Restarted android studio
Restarted computer

(Note: if I start an emulator it works, but I'd prefer to use physical device since I have to scan real barcodes)

Thanks a lot in advance.

回答1:

On Lollipop 5.1

Go to About Phone
Click 7 times on Build Number. Now Developer options are enabled
Go back and Click Developer options
Enable USB debugging under Debugging.

回答2:

Well, I've fixed. The problem in case any faces the same was a Stetho (http://facebook.github.io/stetho/) tab in chrome, the one you open by typing: chrome://inspect/#devices not sure about the reason because it's been open for 2 days now, but it was the cause, once I closed it, it worked.

Found this unaccepted answer here: macbook adb cannot open interface That for sure should be accepted.

EDIT: I've been able to replicate the problem. It happens when you have the devices tab open and try to run a second app that has stetho configured.

回答3:

It happens if your device drivers not installed Please do this.

In Case of PC

Right click my computer select manage select device manager from left panel if your phone drivers not installed there will be yellow alert on driver right click on it select update driver software then select search automatically for update driver software.

Other

Please install the missing drivers of your phone.

回答4:

I had the same problem . What I've done to solve it going to Setting >> Additional Setting >> Developer Option

Now select:

Developer option on
USB debugging on
Install via USB on
USB setting security on
Verify apps over USB

回答5:

OK, what finally worked for me was to go into Settings\Developer options\Select USB Configuration and change it to PTP or MIDI....either one of those worked for me and all of the sudden my phone showed up and I was able to see and run my test app on my android phone.