Slidingmenu+Fragment中，按下home键返回桌面，再重新进入程序时报错问题的解决方法

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最近在学习Slidingmenu+fragment的框架开发，发现个问题。按下home键返回桌面，再重新进入程序时报错。

在部分小内存手机上经常出现这个空指针问题，同时在开发者选项中如果选中了不保留活动选项，也会出现这种问题。

Logcat中出错的相关信息：

XXXX表示包含个人信息，使用X代替.

java.lang.RuntimeException: Unable to start activity ComponentInfo{xxx.xxx/xxx.xxx.activity.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View com.jeremyfeinstein.slidingmenu.lib.app.SlidingActivityHelper.findViewById(int)' on a null object reference     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2406)                                                               at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2466)                                                               at android.app.ActivityThread.access$1200(ActivityThread.java:152)                                                               at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1341)                                                               at android.os.Handler.dispatchMessage(Handler.java:102)                                                               at android.os.Looper.loop(Looper.java:135)                                                               at android.app.ActivityThread.main(ActivityThread.java:5539)                                                               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:960)                                                               at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)                                                            Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View com.jeremyfeinstein.slidingmenu.lib.app.SlidingActivityHelper.findViewById(int)' on a null object reference                                                               at com.jeremyfeinstein.slidingmenu.lib.app.SlidingFragmentActivity.findViewById(SlidingFragmentActivity.java:42)                                                               at xxx.xxx.fragment.ssl.XXXFragment.onCreate(XXXFragment.java:283)                                                               at android.support.v4.app.Fragment.performCreate(Fragment.java:1477)                                                               at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:893)                                                               at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)                                                               at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1086)                                                               at android.support.v4.app.FragmentManagerImpl.dispatchCreate(FragmentManager.java:1879)                                                               at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:215)                                                               at com.jeremyfeinstein.slidingmenu.lib.app.SlidingFragmentActivity.onCreate(SlidingFragmentActivity.java:20)                                                               at xxx.xxx.activity.MainActivity.onCreate(MainActivity.java:38)                                                               at android.app.Activity.performCreate(Activity.java:6013)                                                               at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)                                                               at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2359)                                                               at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2466)                                                               at android.app.ActivityThread.access$1200(ActivityThread.java:152)                                                               at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1341)                                                               at android.os.Handler.dispatchMessage(Handler.java:102)                                                               at android.os.Looper.loop(Looper.java:135)                                                               at android.app.ActivityThread.main(ActivityThread.java:5539)                                                               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:960)                                                               at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

一开始以为是slidingmenu的findViewById出问题了，查了半天没有发现任何情况，后来继续看xxxFragment.class的类283行才发现原因：

在该类中，Textview的初始化赋值写到了onCreate里面，实际是应该写到onCreateView中的。修改后没有发现报错的情况。

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