android 反注册,执行反注册时，页面暂停

问题：

Caused by: java.lang.IllegalStateException: No host

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1194)

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1189)

at android.support.v4.app.FragmentManagerImpl.dispatchPause(FragmentManager.java:2015)

at android.support.v4.app.Fragment.performPause(Fragment.java:2120)

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1077)

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1207)

at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1189)

at android.support.v4.app.FragmentManagerImpl.dispatchPause(FragmentManager.java:2015)

at android.support.v4.app.FragmentController.dispatchPause(FragmentController.java:198)

at android.support.v4.app.FragmentActivity.onPause(FragmentActivity.java:365)

at cn.nubia.accounts.AccountIntroActivity.onPause(AccountIntroActivity.java:566)

at android.app.Activity.performPause(Activity.java:6101)

at android.app.Instrumentation.callActivityOnPause(Instrumentation.java:1462)

at android.app.ActivityThread.performPauseActivity(ActivityThread.java:3424)

at android.app.ActivityThread.performPauseActivity(ActivityThread.java:3397)

at android.app.ActivityThread.handlePauseActivity(ActivityThread.java:3372)

at android.app.ActivityThread.access$1000(ActivityThread.java:164)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1369)

at android.os.Handler.dispatchMessage(Handler.java:102)

at android.os.Looper.loop(Looper.java:147)

at android.app.ActivityThread.main(ActivityThread.java:5513)

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:971)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:766)

现象：

页面白屏，按home键是出现以上异常

问题原因：

执行反注册时，如果content为空，就会出现无限暂时。

本人的反注册放在onDestroy中，执行完onDestroyView后，卡在了onDestroy。

解决方法：

判断content是否为空。