in-app billing doesn't work: “IAB Helper is not set up”
问题 I tried to include in-app billing in my app and for the purpose of testing, based the whole procedure on the "TrivialDrive" example for version 3 of in-app billing (and implementing the unmodified versions of the IAB files as supplied in the "util" subdirectory of the demo), but it doesn't work for me - on LogCat, just before the app terminates with an error, it gives the message "In-app billing error: Illegal state for operation (launchPurchaseFlow): IAB Helper is not set up. " (right after