android studio: release apk is not signed

Question

* I have rephrased the post since originally posted *

When I try to run a just-built release apk, I get an error \"the apk for your currently selected v

Answer 1

In https://developer.android.com/studio/publish/app-signing#secure-shared-keystore it is written that you shouldn't keep credentials information in build.gradle and VCS. So create a signing config file (Build > Generate Signed APK...), then do so.

Create a file named keystore.properties in the root directory of your project. This file should contain your signing information, as follows:

storePassword=myStorePassword
keyPassword=mykeyPassword
keyAlias=myKeyAlias
storeFile=myStoreFileLocation

In your module's build.gradle file, add code to load your keystore.properties file before the android {} block.

// Create a variable called keystorePropertiesFile, and initialize it to your
// keystore.properties file, in the rootProject folder.
def keystorePropertiesFile = rootProject.file("keystore.properties")

// Initialize a new Properties() object called keystoreProperties.
def keystoreProperties = new Properties()

// Load your keystore.properties file into the keystoreProperties object.
keystoreProperties.load(new FileInputStream(keystorePropertiesFile))

android {
    ...
}

You can refer to properties stored in keystoreProperties using the syntax keystoreProperties['propertyName']. Modify the signingConfigs block of your module's build.gradle file to reference the signing information stored in keystoreProperties using this syntax.

android {
    signingConfigs {
        config {
            keyAlias keystoreProperties['keyAlias']
            keyPassword keystoreProperties['keyPassword']
            storeFile file(keystoreProperties['storeFile'])
            storePassword keystoreProperties['storePassword']
        }
    }
    ...
}

Optionally in build.gradle you can add:

buildTypes {
    release {
        ...
        signingConfig signingConfigs.config
    }
}

Now you may make a signed apk. Don't forget to exclude keystore.properties from VCS.