How to get the build/version number of your Android application?

Question

I need to figure out how to get or make a build number for my Android application. I need the build number to display in the UI.

Do I have to do something with

Answer 1

Useful for build systems: there is a file generated with your apk called output.json which contains an array of information for each generated APK, including the versionName and versionCode.

eg

[
    {
        "apkInfo": {
            "baseName": "x86-release",
            "enabled": true,
            "filterName": "x86",
            "fullName": "86Release",
            "outputFile": "x86-release-1.0.apk",
            "splits": [
                {
                    "filterType": "ABI",
                    "value": "x86"
                }
            ],
            "type": "FULL_SPLIT",
            "versionCode": 42,
            "versionName": "1.0"
        },
        "outputType": {
            "type": "APK"
        },
        "path": "app-x86-release-1.0.apk",
        "properties": {}
    }
]