Getting the error "device not found" when running a apk file from Android emulator

I am trying to install an apk file from command prompt but getting an err开发者_如何学Goor "Device not found".

try "adb devices" first and see the list of devices connected.
If the phone does not appear, do this :
"adb kill-server" wait a few seconds then "adb start-server"
If the phone appears in the list but its name is ?????, you have an issue of permission.
If the phone appears fine, you might have an issue in your command. Then check the following :

Is your phone in debugging mode?
Have you added the debuggable tag to the manifest of your application?
is the phone properly connected with the cable to your computer?
Have you done everything correctly on this page.

Fist turn on the emulator and then go to prompt and type:

adb install yourfile

Try adb devices If you don't see your simulator device in the list although its on, you probably have to start the server. Execute adb start-server. Then once the server is up again check for device by using adb devices command. Your device will be in the list Now try to install the application. After installatio the application will be available in the menu.