How to record screen with Android Studio

Go to your menu

• View -> Tool Windows -> Android

You will find the record icon at the bottom left corner.

If you are using an AVD, make sure "Use host GPU" is disabled.

To take a video recording of your app:

• Start your app as described in Run your App in Debug Mode.
• Click Android to open the Android DDMS tool window.
• Click Screen Record on the left side of the Android DDMS tool window.
• Click Start Recording.
• Interact with your app.
• Click Stop Recording.
• Enter a file name for the recording and click OK.

Source: https://developer.android.com/tools/debugging/ddms.html

In newer versions of Android Studio it requires an external Android phone to record screen from preferably with a resolution of at least 720p. Since the internal runs on the virtual memory it can't be recorded and is therefore disabled as it can't both record and run emulator at same time. I'm running Android Studio 2.3.2 which is the latest and the one I experienced this on. But when I closed the emulator and connected my HTC One M9 it automatically enabled recording button to record the phone instead of the emulated device.
Check the images below and the difference between them in the red circles:

First image, emulated device on the computer:

Second image, personal device connected to computer:

Maybe your device does not support the screen recorder, there are many devices which does not support screen recorder thus this is device issue. If you want to record your app screen then simply run the app on android emulator or on genymotion and start your desktop screen recorder and adjust the desktop screen to fit emulator. There are many screen recorder for PC but i prefer cam studio 8. Thanks

Now you can also record video from Android emulator to follow below option:

• Select more option
• Then select Record screen option.

Check below screenshot: