In App Billing - Rapid Device Orientation - causes crash (IllegalStateException)

Question

I implemented In-app Billing (v3) according to Android's Implementing In-app Billing guide.

All works fine, until I rotate the device, then immediately rotate it back to it's original orientation. Actually, sometimes it works, and sometimes it crashes with:

java.lang.IllegalStateException: IabHelper was disposed of, so it cannot be used.

Seems this is related to the asynchronous nature of IAB, though I'm not positive.

Any thoughts?

Answer 1

You're probably getting the exception because somewhere in the activity lifecycle, you called mHelper.dispose(), then tried to use that same disposed instance later on. My recommendation is to only dispose of mHelper in onDestroy() and recreate it in onCreate().

However, you will run into another problem with IabHelper and device rotation. The problem goes like this: in your activity's onCreate(), you create the IabHelper instance mHelper and set it up. Later, you call mHelper.launchPurchaseFlow(...) and the IAB popup dialog appears floating above your activity. Then you rotate the device, and the IabHelper instance gets disposed of in onDestroy(...) then recreated in onCreate(...). The IAB dialog is still showing, you press the purchase button, and the purchase completes. onActivityResult() is then called on your activity, and you naturally call mHelper.handleActivityResult(...). The problem is, launchPurchaseFlow(...) has never been called on the recreated instance of IabHelper. IabHelper only handles the activity result in handleActivityResult(...) if launchPurchaseFlow(...) has been previously called on the current instance. Your OnIabPurchaseFinishedListener will never be called.

My solution to this was to modify IabHelper to allow you to tell it to expect handleActivityResult(...) without calling launchPurchaseFlow(...). I added the following to IabHelper.java

public void expectPurchaseFinished(int requestCode, OnIabPurchaseFinishedListener listener)
{
    mRequestCode = requestCode;
    mPurchaseListener = listener;
}

This will cause IabHelper to call onIabPurchaseFinished(...) on the listener when handleActivityResult(...) is called. Then, you do this:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) 
{
    mHelper.expectPurchaseFinished(requestCode, mPurchaseFinishedListener);
    mHelper.handleActivityResult(requestCode, resultCode, data);
}

My entire copy of IabHelper can be found here https://gist.github.com/benhirashima/7917645. Note that I updated my copy of IabHelper with the version found in this commit, which fixes a few bugs and has not been published in the Android SDK Manager. Also note that there are newer commits, but they contain new bugs and should not be used.

Answer 2

Here's what I did:

The code to instantiate the IabHelper and call startSetup() is within onCreate(), so it will be recreated when the device is rotated, so long as you aren't handling configuration changes on your own.

Also, be certain you are calling .handleActivityResult() at the beginning of onActivityResult(). This will ensure that your IabHelper reference is correctly cleaned up after the purchase dialog is closed.

With those two things in place, you shouldn't see any more crashes. But you will notice one more thing:

If you start the purchase dialog with a call to launchPurchaseFlow() and then rotate the device, the dialog will stay open, but now your Activity's IabHelper reference has been overwritten since onCreate() is called on device rotation. Because of this, when you close the dialog, the new IabHelper's handleActivityResult() method is called, but it doesn't match up with the requestCode you passed to launchPurchaseFlow() earlier, so your onPurchaseFinishedListener will not be notified. To handle this case (device rotations when the dialog is open), you'll need to handle the requestCode yourself inside of onActivityResult(). Since the dialog was closed, you'll want to mimic what you did inside your onPurchaseFinishedListener (discover if the user actually bought something). I just made a call to queryInventoryAsync() to find that out.

I'm not sure if that is the ideal solution, but it works well for me. I tried hanging on to the IabHelper reference like you did, but I saw weird issues where it would lose its setup state but wouldn't allow me to re-set it up.

A final thing I did was update billing util classes with the latest from the android source. There are some bug fixes that haven't been pushed to the SDK manager. Most of them are questionable null checks, but there are some improvements to prevent crashes:

latest changeset