我是android新手，我的第一个应用程序最近完成了。我想在我的应用程序中设置IAB（在应用程序计费中），我测试了我的应用程序，我遇到了以下问题： 1 - 当我点击＆＃34;买＆＃34;按钮eveything正常，付款操作正常运行。但当我关闭应用程序并单击按钮时，我有以下错误。
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4015)
at android.view.View.performClick(View.java:4764)
at android.view.View$PerformClick.run(View.java:19844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5376)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4010)
at android.view.View.performClick(View.java:4764)
at android.view.View$PerformClick.run(View.java:19844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5376)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
Caused by: java.lang.IllegalStateException: Can't start async operation
(launchPurchaseFlow) because another async operation(refresh inventory) is in progress.
at
com.example.android.trivialdrivesample.util.IabHelper.flagStartAsync(IabHelper.java:812)
at com.example.android.trivialdrivesample.util.IabHelper.launchPurchaseFlow(IabHelper.java:376) at com.example.android.trivialdrivesample.util.IabHelper.launchPurchaseFlow(IabHelper.java:341) at com.example.farshid.columnanalysis.MainActivity.gotoColumnAnalysis(MainActivity.java:186) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at android.view.View$1.onClick(View.java:4010) at android.view.View.performClick(View.java:4764) at android.view.View$PerformClick.run(View.java:19844) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5376) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
2 - 我有另一个问题:)当我购买我的应用程序时，如何更改我的按钮背景（例如将其测试从购买更改为阅读）
如何修复它们... tnx in advanced。