android - Android in app billing 无法启动异步操作

Question

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一个 IAB（应用程序内计费），我测试了我的应用程序并且遇到了以下问题： 1-当我点击“购买”按钮时，一切正常并且支付操作正常运行。但是当我关闭应用程序并单击按钮时，出现以下错误。

    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-我还有一个问题 :) 当某人购买我的应用程序时，如何更改按钮背景（例如将其测试从购买更改为阅读）

我该如何修复它们... tnx 高级。