发布使用旧版 Google Play 结算

Question

I've been searching for hours but I can't seem to find an answer to what is the difference between Google Play Billing Library and In-app Billing API and if one of them is causing the error message below:

Release uses an old version of Google Play Billing

I'm reading about Google Play Billing Library here: https://developer.android.com/google/play/billing/integrate and the In-app Billing API here: http://android.cn-mirrors.com/google/play/billing/billing_overview.html

I'm really confused, the whole confusion started because I was trying to deploy an old app on Google play started by someone else long ago, but got the error:

Release uses an old version of Google Play Billing

So I started to look at what version of the billing library the app uses but I couldn't find it. From the AndroidManifest.xml , I see:

<uses-permission android:name="com.android.vending.BILLING" />

And from one of the files in the android project I see:

import com.android.vending.billing.IInAppBillingService;

As you can see it doesn't really tell me what version the library is.

Having no experience in Google play store, I started looking up Google Play Billing Library and I'm seeing:

To be compliant, apps must import version 4.0.0 or higher of the Play Billing Library. Note that Billing dependencies would be found only in APKs that require the com.android.vending.BILLING permission.

Problem is I'm not seeing anything that's importing the Google Play Billing Library dependency in the project, ie:

dependencies {
    def billing_version = "5.0.0"

    implementation "com.android.billingclient:billing:$billing_version"
}

This makes me thing, perhaps the project is not using the Google Play Billing Library at all.

So I started to look at IInAppBillingService which led me here: http://android.cn-mirrors.com/google/play/billing/billing_overview.html . This seems to be an old library? Which is making me think that's the reason why I'm getting Release uses an old version of Google Play Billing when I'm trying to deploy the app.

This leads me to my question:

1. Am I getting the error Release uses an old version of Google Play Billing because the project is using IInAppBillingService which is very old?

2. What is the difference between Google Play Billing Library and In-app Billing API .

Answer 1

IInAppBillingService.aidl is obsolete and might not even be considered anymore.
What the difference in between the library and the API is, should possibly be obvious.