如何解决活动重新启动和片段重新创建时视图绑定空指针异常

问：

每当我的MainActivity由于暗模式的更改而重新启动时，我尝试单击我得到nullpointer异常。 错误如下

我有一个BaseFragment

lateinit var mContext:Context
lateinit var mActivity:Activity
var myId = ""

val firebaseMethods: FirebaseMethods by lazy { FirebaseMethods(requireActivity()) }

override fun onDestroy() {
    super.onDestroy()
    removeListeners()
}
override fun onAttach(context: Context) {
    super.onAttach(context)
    showLogI("onAttach")
}
override fun onDetach() {
    super.onDetach()
    showLogI("onDetach")
}
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    mContext = requireContext()
    mActivity = requireActivity()
    showLogI("onCreate")
    if(getCurrentUser() != null){
        myId = getCurrentUserId()
    }
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?)
: View {
    showLogI("onCreateView")
    val view = setContentView(inflater, container, savedInstanceState)
    return view
}

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    initView(view)
    setListener()
    initData()
}
protected abstract fun setContentView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?):View
protected abstract fun setListener()
protected abstract fun initData()

我还有一个PostFragment

var posts:ArrayList<Post> = arrayListOf()
var pgPosts:ArrayList<Post> = arrayListOf()
var ids:ArrayList<String> = arrayListOf()

val keys:ArrayList<String> = arrayListOf()
var totalSize = 0
var query: Query? = null

var postAdapter:PostAdapter? = null

var counter = 0
var adUnit = ""
var adminId = ""

override fun onDestroy() {
    super.onDestroy()
    postAdapter?.removeListeners()
    destroyAds()
}
private var _binding: FragmentPostBinding? = null
private val binding get() = _binding!!

override fun onDestroyView() {
    super.onDestroyView()
    _binding = null
}

override fun setContentView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View {
    _binding = FragmentPostBinding.inflate(inflater, container, false)
    return binding.root
}

override fun setListener() {

}


override fun initData() {
    getArgs()
    toggleOrientation()
    showProgress()
    setAdapter()

    val spannableString = "No Internet Connection. Retry".createSpan("Retry"){ spannableString, start, end ->
        mContext.setSpan(spannableString, "click", start, end, R.color.green){readPosts()}
    }
   
    if (mContext.isConnectingToInternet()) readPosts() else hideProgressWithSpan(spannableString)

    adUnit = mContext.getString(R.string.ads_unit_video)
    firebaseMethods.getAdmin { admin->
        adminId = admin.admin_id
        //adUnit = admin.native_ads_unit
    }
}
fun changeLayout(orientation:String){
    this.orientation = orientation
    toggleOrientation()
    setAdapter()
}
fun toggleOrientation(){
    if (orientation == "big") {
        max = 5
        binding.recyclerview.lm()
    } else if (orientation == "small") {
        max = 15
        binding.recyclerview.lm("grid", 3)
    }
}

我得到这个空指针异常

E/AndroidRuntime：致命异常：main 进程：com.wh，PID：26862 java.lang.NullPointerException 在 com.wh.ui.fragment.post.PostFragment.getBinding（PostFragment.kt：101） 在 com.wh.ui.fragment.post.PostFragment.toggleOrientation（PostFragment.kt：160） 在 com.wh.ui.fragment.post.PostFragment.changeLayout（PostFragment.kt：154）