安卓应用运行时出现错误

Question

我无法弄清楚在应用程序运行时导致此错误的原因。它会导致应用停止。休眠主线程以完成异步线程的执行是否是一种错误的做法。如果是这样，为什么以及什么是好的做法？

java.lang.IllegalStateException: Could not execute method for android:onClick
at android.view.View$DeclaredOnClickListener.onClick(View.java:4707)
at android.view.View.performClick(View.java:5619)
at android.view.View$PerformClick.run(View.java:22295)
at android.os.Handler.handleCallback(Handler.java:754)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:163)
at android.app.ActivityThread.main(ActivityThread.java:6342)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:880)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:770)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.view.View$DeclaredOnClickListener.onClick(View.java:4702)
at android.view.View.performClick(View.java:5619) 
at android.view.View$PerformClick.run(View.java:22295) 
at android.os.Handler.handleCallback(Handler.java:754) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:163) 
at android.app.ActivityThread.main(ActivityThread.java:6342) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:880) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:770) 
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at com.example.sairahul5223.e_bot.Main4Activity.onButtonClickName43(Main4Activity.java:330)
at java.lang.reflect.Method.invoke(Native Method) 
at android.view.View$DeclaredOnClickListener.onClick(View.java:4702) 
at android.view.View.performClick(View.java:5619) 
at android.view.View$PerformClick.run(View.java:22295) 
at android.os.Handler.handleCallback(Handler.java:754) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:163) 
at android.app.ActivityThread.main(ActivityThread.java:6342) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:880) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:770) 

Answer 1

第一件事：我们不会让主线程休眠，因为这会导致应用程序无响应 (ANR( 错误。

为了获取异步任务的结果，我们通常使用回调来确定任务的状态。看看这个答案，给你一个想法：如何获得OnPostExecute((的结果到主活动，因为AsyncTask是一个单独的类？