I've been trying since hours to connect my Huawei P10, Android 8.0.0 with my Android Studio 3.0. But it doesn't work. It won't get shown either in adb devices -l and not in the Android Studio Select Deployment Target window. But my computer and the smartphone says it is connected. I chose every mode, only charging, file-transfer and photo mode. Every mode doesn't work. And yes, the USB-Debugging mode is activated and even for only-charging. I tried following this guide https://developer.android.com/studio/run/device.html, but yeah... doesn't help. The charging cable is a USB-C cable which you get from buying the huawei p10, so I would say it's the original one. And I tried 4 USB Ports. 2 USB 3.0, 2 USB 2.0. All say it is connected, but not with Android Studio or with adb. Weird. btw, I never received the RSA confirmation like it should.
Please follow these steps to debug your Huawei P10/P10 Plus.
Turn on your Huawei P10/P10 Plus, go to Settings.
Under Settings option, select About phone.
Scroll down the screen and tap Build number several times until you see a message that says "You are now a developer!".
Select on the Back button and you will see the Developer options menu under Settings, and select Developer options.
Enable "USB debugging" mode, there will be a pop-up "Allow USB debugging?", click "OK".
Connect your phone to computer, you will see "Allow access to device data?", click "YES, ALLOW ACCESS".