资源回收的时候空指针了

[Flipped199]

2020-05-30 11:16:54.573 4046-4046 E/AndroidRuntime: FATAL EXCEPTION: main
Process: xxx, PID: 4046
java.lang.RuntimeException: Unable to destroy activity {xxx/com.ess.filepicker.activity.SelectFileByScanActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean androidx.fragment.app.FragmentManagerImpl.isDestroyed()' on a null object reference
at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:4167)
at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:4185)
at android.app.ActivityThread.-wrap6(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1521)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean androidx.fragment.app.FragmentManagerImpl.isDestroyed()' on a null object reference
at androidx.fragment.app.Fragment.performDetach(Fragment.java:2849)
at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1034)
at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1238)
at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1303)
at androidx.fragment.app.FragmentManagerImpl.dispatchStateChange(FragmentManagerImpl.java:2659)
at androidx.fragment.app.FragmentManagerImpl.dispatchDestroy(FragmentManagerImpl.java:2644)
at androidx.fragment.app.FragmentController.dispatchDestroy(FragmentController.java:329)
at androidx.fragment.app.FragmentActivity.onDestroy(FragmentActivity.java:366)
at androidx.appcompat.app.AppCompatActivity.onDestroy(AppCompatActivity.java:233)
at com.ess.filepicker.activity.SelectFileByScanActivity.onDestroy(SelectFileByScanActivity.java:122)
at android.app.Activity.performDestroy(Activity.java:6864)
at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1153)
at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:4154)
at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:4185) 
at android.app.ActivityThread.-wrap6(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1521) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6077) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) 

[roomanl]

我改成androidx也出现这个问题了。BaseFileFragment文件onDetach方法里面childFragmentManager.set(this, null);注释即可解决