Android in-app billing: Can't start async operation because another async operation (is in progress)

A simple tricky solution

before calling purchaseItem method just add this line

  if (billingHelper != null) billingHelper.flagEndAsync();

so your code looks this way

 if (billingHelper != null) billingHelper.flagEndAsync();
 purchaseItem("android.test.purchased");

Note: don't forget to make public flagEndAsync() method in IabHelper if you call it from another package.

Make sure that you call the IabHelper's handleActivityResult in the Activity's onActivityResult, and NOT in the Fragment's onActivityResult.

The following code snippet is from TrivialDrive's MainActivity:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    Log.d(TAG, "onActivityResult(" + requestCode + "," + resultCode + "," + data);
    if (mHelper == null) return;

    // Pass on the activity result to the helper for handling
    if (!mHelper.handleActivityResult(requestCode, resultCode, data)) {
        // not handled, so handle it ourselves (here's where you'd
        // perform any handling of activity results not related to in-app
        // billing...
        super.onActivityResult(requestCode, resultCode, data);
    }
    else {
        Log.d(TAG, "onActivityResult handled by IABUtil.");
    }
}

Update:

• There is now a In-app Billing Version 3 API (what was the version in 2013?)
• The code sample has moved to Github. Snippet above edited to reflect current sample, but is logically the same as before.

This was not easy to crack but I found the needed workarounds. Quite disappointed with Google lately, their Android web sites have become a mess (very hard to find useful info) and their sample code is poor. When I was doing some Android development a few years ago it all went so much easier! This is yet another example of that...

Indeed IabUtil is buggy, it does not properly call off its own async tasks. The complete set of necessary workarounds to stabilise this thing:

1) make method flagEndAsync public. It is there, just not visible.

2) have every listener call iabHelper.flagEndAsync to make sure the procedure is marked finished properly; it seems to be needed in all listeners.

3) surround calls with a try/catch to catch the IllegalStateException which may occur, and handle it that way.

I ended up doing something similar to Kintaro. But added mHelper.flagEndAsync() to the end of the catch. The user still gets the toast but by the next time they push the purchase button, the async operation has been killed and the purchase button is ready to go again.

if (mHelper != null) {
    try {
    mHelper.launchPurchaseFlow(this, item, RC_REQUEST, mPurchaseFinishedListener, "");
    }       
    catch(IllegalStateException ex){
        Toast.makeText(this, "Please retry in a few seconds.", Toast.LENGTH_SHORT).show();
        mHelper.flagEndAsync();
    }
}

Find flagEndAsync() inside IabHelper.java file and change it to a public function.

Before trying purchase call flagEndAsync() for your IabHelper

You must do somthig like this code :

mHelper.flagEndAsync();
mHelper.launchPurchaseFlow(AboutActivity.this, SKU_PREMIUM, RC_REQUEST, mPurchaseFinishedListener, "payload-string");