Android Studio Connection Real machine does not recognize

I am also a beginner. Write the wrong, please the great God more criticism! Great honor!!

It is highly recommended to use a real-machine test. Unless it is the last minute to test each Android system version.

I met the reasons for not even the following:

1-Phone setup issues. Open USB Debug Method: Phone Settings-developer Options-USB Debug-Tick

2--Data line problem. Some data lines can only be used for charging, and some may be connected to storage. The recognition method is simple. Plug in the machine with a USB storage device prompt can be used. In addition, if the data line is exposed to the skin. Just throw it away. Ten bucks, eight bucks, is better than a good afternoon for this problem.

3-whether to download the corresponding mobile version of the SDK, in the case of Android studio, after opening the SDK Manager. See if the SDK that corresponds to the system version number you are using is downloaded. No, just hurry down. Mobile phone corresponding to the Android version view method is phone settings-about mobile-Android version

This is the situation I have encountered at present. If you haven't solved your problem yet. It is not enough to show that I have encountered difficulties.

Hope to solve your problem after. Be able to give an explanation of your situation and how to solve it in the comments. Thank you

Android Studio Connection Real machine does not recognize