Install APK generated by Android Studio

Go to File > Build APK, once the apk is generated, a message like this will appear

das click on "show in explorer", copy the apk to your phone and you can install it without problems.

  

So I went to Build > Generate Signed APK, I generated the JAR file   and then I create my APK.

Although .jar and .apk are compressed files of a package, the file suitable for installation is the one with extension .apk

  

But when I'm going to install my App on my cell phone, it tells me that I do not know   can.

You do not specify in what form you try to install it, if it is not by means of the ADB and you install it by means of a download of the .apk you must ensure that your device allows installations of "unknown sources" ("unknown sources").

  

My cell phone has an API 19 and in the Gradle the min SDK version is 15.

" This is not a problem, on the contrary, your API is greater than the minimum defined version, which is 15.

  

It's already solved, when I do Build > Generate Signed APK. it is generated   an app-release.apk file. But when I simply do Build> Build   APK. I got an app-debug.apk file. And that if I can install it.

Both an application generated with a production Keystore and one generated with debug can be installed on a device, if this allows installation of "unknown origin" and something important is to ensure that you do not have a version of the application since it will not allow to overwrite it because it has the same versionCode .

.APK RELEASE

If you generate the .apk by:

Build > Generate Signed APK

The generated .apk would be signed with a keystore that is supposed to be for production, which was previously created for this purpose. This .apk would be considered the right one to upload to the Google Play Store.

.APK DEBUG

If you generate the .apk by:

Build APK

A signed .apk would be generated with the debug keystore, which is usually found in the route:

:\users\<usuario>\.android\debug.keystore

Even if you do not generate your .apk with the previous options, with the simple fact of generating your project and uploading it to the device, a .apk is created which you can use for installation and it is in the route:

   <proyecto>\app\builds\outputs\apk\

If you could install the debug APK without problems, but the APK release did not allow you (the message Application not installed appeared), I solved it in the following way:

I went to Build / Generate Signed APK ...

As you probably already did, in the KeyStore Path you will see the key generated previously. You leave it like this, and put the passwords that you put the first time you generated the Signed APK.

And in the next, TILDAS BOTH "V1 (Jar Signature)" and "V2 (Full APK Signature)", and you hit Finish.

The first time I created it, I only had V2 marked with tilde and I had the same problem. I marked both options, I generated the APK Release again, and I could install it.

And if it's the first time you generate the APK Release, simply check both options when they appear.

The same thing happened to me, as long as I generated my apk from Build> Build APK. I could install and un-install the apk as many times as they were without any problem, but instead if I generated the Build > Generate Signed APK, when I passed the apk to the phone and tried to install it, it only allowed me one occasion, the same one in which I got the following message:

until then everything was fine if I selected "INSTALL IN ANY WAY", but what happened if I uninstalled the app and wanted to reinstall it (a possible scenario), the following happened:

so I solved the problem by disabling play protect , which I achieved (within Google Play) > Menu > Play Protect > Search for security threats (disable).