diff --git a/app/src/main/java/com/novel/read/activity/NovelMainActivity.kt b/app/src/main/java/com/novel/read/activity/NovelMainActivity.kt
index d719676..c47a658 100644
--- a/app/src/main/java/com/novel/read/activity/NovelMainActivity.kt
+++ b/app/src/main/java/com/novel/read/activity/NovelMainActivity.kt
@@ -26,7 +26,7 @@ import kotlinx.android.synthetic.main.activity_main.*
 
 class NovelMainActivity : NovelBaseActivity() {
 
-    private var mCurrentFrag: Fragment? = null
+    private lateinit var mCurrentFrag: Fragment
     private lateinit var mMainFragment: BookFragment
     private lateinit var mRecommendFragment: RecommendFragment
     private lateinit var mStackFragment: StackFragment
@@ -35,11 +35,6 @@ class NovelMainActivity : NovelBaseActivity() {
     //记录用户首次点击返回键的时间
     private var firstTime: Long = 0
 
-    @SuppressLint("MissingSuperCall")
-    override fun onSaveInstanceState(outState: Bundle) {
-        super.onSaveInstanceState(outState)
-    }
-
     override val layoutId: Int get() =  R.layout.activity_main
 
     override fun initView() {
@@ -84,13 +79,10 @@ class NovelMainActivity : NovelBaseActivity() {
     private fun switchFragment(targetFragment: Fragment) {
         val transaction = supportFragmentManager.beginTransaction()
         if (!targetFragment.isAdded) {
-            //第一次使用switchFragment()时currentFragment为null，所以要判断一下
-            if (mCurrentFrag != null) {
-                transaction.hide(mCurrentFrag!!)
-            }
+            transaction.hide(mCurrentFrag)
             transaction.add(R.id.fl_content, targetFragment, targetFragment.javaClass.name)
         } else {
-            transaction.hide(mCurrentFrag!!).show(targetFragment)
+            transaction.hide(mCurrentFrag).show(targetFragment)
         }
         mCurrentFrag = targetFragment
         transaction.commit()
diff --git a/app/src/main/java/com/novel/read/adapter/BookAdapter.kt b/app/src/main/java/com/novel/read/adapter/BookAdapter.kt
index 8c6cb1a..53694ca 100644
--- a/app/src/main/java/com/novel/read/adapter/BookAdapter.kt
+++ b/app/src/main/java/com/novel/read/adapter/BookAdapter.kt
@@ -18,7 +18,7 @@ import com.novel.read.utlis.GlideImageLoader
 import java.util.ArrayList
 
 class BookAdapter(private val mList: List<CollBookBean>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
-    private var mContext: Context? = null
+    private lateinit var mContext: Context
 
     private var mClickListener: OnItemClickListener? = null
     private var mEdit: Boolean = false
@@ -35,9 +35,7 @@ class BookAdapter(private val mList: List<CollBookBean>) : RecyclerView.Adapter<
         }
 
     override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): RecyclerView.ViewHolder {
-        if (mContext == null) {
-            mContext = viewGroup.context
-        }
+        mContext = viewGroup.context
         val view: View
         if (i == VALUE_ITEM) {
             view = LayoutInflater.from(mContext).inflate(R.layout.rlv_item_book, viewGroup, false)
@@ -61,7 +59,7 @@ class BookAdapter(private val mList: List<CollBookBean>) : RecyclerView.Adapter<
                 } else {
                     viewHolder.mIvGeng.visibility = View.GONE
                 }
-                GlideImageLoader.displayCornerImage(mContext!!, mList[i].cover, viewHolder.mIvBook)
+                GlideImageLoader.displayCornerImage(mContext, mList[i].cover, viewHolder.mIvBook)
                 viewHolder.itemView.setOnClickListener {
                     viewHolder.mIvCheck.isSelected = !mList[i].isSelect
                     mList[i].isSelect = !mList[i].isSelect
@@ -88,7 +86,7 @@ class BookAdapter(private val mList: List<CollBookBean>) : RecyclerView.Adapter<
                         viewHolder.mIvGeng.visibility = View.GONE
                     }
                     GlideImageLoader.displayCornerImage(
-                        mContext!!,
+                        mContext,
                         mList[i].cover,
                         viewHolder.mIvBook
                     )
@@ -96,7 +94,7 @@ class BookAdapter(private val mList: List<CollBookBean>) : RecyclerView.Adapter<
                         val intent = Intent(mContext, NovelReadActivity::class.java)
                         intent.putExtra(NovelReadActivity.EXTRA_IS_COLLECTED, true)
                         intent.putExtra(NovelReadActivity.EXTRA_COLL_BOOK, mList[i])
-                        mContext!!.startActivity(intent)
+                        mContext.startActivity(intent)
                     }
                 }
             }