如何检测Android App已从x版本升级到y版本？

Question

I have a problem with my android app for own educational reason.

Is there a ready solution to detect that the app has now been updated from version x to y? Because I want to migrate some data once only if the app was installed in a special version before.

Thanks.

Answer 1

The easiest way is to store the last known version of your application in SharedPreferences, and check that when the app is launched.

You can get the current version code of your application with BuildConfig.VERSION_CODE .

For example:

@Override
public void onStart() {
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
    int lastKnownVersion = prefs.getInt("lastKnownAppVersion", 0);

    if (lastKnownVersion < BuildConfig.VERSION_CODE) {
        // Your app has been updated

        prefs.edit().putInt("lastKnownAppVersion", BuildConfig.VERSION_CODE);
    }
}

Registering a BroadcastReceiver to listen for the ACTION_MY_PACKAGE_REPLACED intent will tell you when your package is replaced (ie updated), but that won't tell you what version was previously installed.

Answer 2

Here is a simple way that can solve your problem. In your code you can easily get the app versionCode and versionName. In your home activity you check isAppUpdated(). if current APP VERSION_NAME is not matched with stored VERSION_NAME then app is updated.

Here is sample code:

Save VersionName in preferences:

public static void saveVersionNameAndCode(Context context){
        try{
            PackageInfo packageInfo = context.getPackageManager()
                    .getPackageInfo(context.getPackageName(), 0);
            int versionCode = packageInfo.versionCode;
            String versionName=packageInfo.versionName;

            CommonTasks.showLog("Saving APP VersionCode and Version Name");

            // SAVE YOUR DATA

        }catch(Exception e){
        }
    }

Check App is Upgraded:

public static boolean isAppUpdated(Context context){
        boolean result=false;
        try{
            PackageInfo packageInfo = context.getPackageManager()
                    .getPackageInfo(context.getPackageName(), 0);
            int versionCode = packageInfo.versionCode;
            String versionName=packageInfo.versionName;

            String prevVersionName= GET STORED VERSION_NAME;
            if(prevVersionName!=null && !prevVersionName.equals("") &&
                    !prevVersionName.equals(versionName)){
                showLog("App Updated");
                result=true;
            }else{
                showLog("App Not updated");
            }

        }catch(Exception e){
        }
        return result;
    }

here, if isAppUpdated() return true means your app is updated.

Note, After checking upgrade issue, you must have to update the sharedPreferences. :)