項(xiàng)目用的是這個(gè)人的框架
https://github.com/CymChad/BaseRecyclerViewAdapterHelper

測(cè)試發(fā)現(xiàn)rv底層拋出了一個(gè)異常，不斷滑動(dòng)加載更多出現(xiàn)的

ViewHolder views must not be attached when created. Ensure that you are not passing 'true' to the attachToRoot parameter of LayoutInflater.inflate(..., boolean attachToRoot)

看了下大佬的框架好像沒(méi)人解決過(guò)這個(gè)問(wèn)題

image.png

錯(cuò)誤異常如下代碼

java.lang.IllegalStateException: ViewHolder views must not be attached when created. Ensure that you are not passing 'true' to the attachToRoot parameter of LayoutInflater.inflate(..., boolean attachToRoot)
    at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:6687)
    at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5869)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5752)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5748)
    at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2232)
    at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1559)
    at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1519)
    at android.support.v7.widget.LinearLayoutManager.scrollBy(LinearLayoutManager.java:1333)
    at android.support.v7.widget.LinearLayoutManager.scrollVerticallyBy(LinearLayoutManager.java:1077)
    at android.support.v7.widget.RecyclerView.scrollByInternal(RecyclerView.java:1815)
    at android.support.v7.widget.RecyclerView.onTouchEvent(RecyclerView.java:3076)
    at android.view.View.dispatchTouchEvent(View.java:9939)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2663)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2344)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2669)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2358)
    at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:411)
    at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1810)

百度搜了幾篇文章都說(shuō)

image.png

可是我看了作者的代碼本來(lái)就這樣寫

image.png

懷著好奇的跟蹤了下源碼，源碼路徑
/frameworks/support/v7/recyclerview/src/main/java/androidx/recyclerview/widget/RecyclerView.java

/**
6739         * This method calls {@link #onCreateViewHolder(ViewGroup, int)} to create a new
6740         * {@link ViewHolder} and initializes some private fields to be used by RecyclerView.
6741         *
6742         * @see #onCreateViewHolder(ViewGroup, int)
6743         */
6744        @NonNull
6745        public final VH createViewHolder(@NonNull ViewGroup parent, int viewType) {
6746            try {
6747                TraceCompat.beginSection(TRACE_CREATE_VIEW_TAG);
6748                final VH holder = onCreateViewHolder(parent, viewType);
6749                if (holder.itemView.getParent() != null) {
6750                    throw new IllegalStateException("ViewHolder views must not be attached when"
6751                            + " created. Ensure that you are not passing 'true' to the attachToRoot"
6752                            + " parameter of LayoutInflater.inflate(..., boolean attachToRoot)");
6753                }
6754                holder.mItemViewType = viewType;
6755                return holder;
6756            } finally {
6757                TraceCompat.endSection();
6758            }
6759        }

從代碼來(lái)看holder.itemView.getParent() 不為null就會(huì)拋出這個(gè)異常，然后我再看了看final VH holder = onCreateViewHolder(parent, viewType);
可能我很久沒(méi)寫代碼，發(fā)現(xiàn)onCreateViewHolder是要自己去實(shí)現(xiàn)邏輯的

 /**
6659         * Called when RecyclerView needs a new {@link ViewHolder} of the given type to represent
6660         * an item.
6661         * <p>
6662         * This new ViewHolder should be constructed with a new View that can represent the items
6663         * of the given type. You can either create a new View manually or inflate it from an XML
6664         * layout file.
6665         * <p>
6666         * The new ViewHolder will be used to display items of the adapter using
6667         * {@link #onBindViewHolder(ViewHolder, int, List)}. Since it will be re-used to display
6668         * different items in the data set, it is a good idea to cache references to sub views of
6669         * the View to avoid unnecessary {@link View#findViewById(int)} calls.
6670         *
6671         * @param parent The ViewGroup into which the new View will be added after it is bound to
6672         *               an adapter position.
6673         * @param viewType The view type of the new View.
6674         *
6675         * @return A new ViewHolder that holds a View of the given view type.
6676         * @see #getItemViewType(int)
6677         * @see #onBindViewHolder(ViewHolder, int)
6678         */
6679        @NonNull
6680        public abstract VH onCreateViewHolder(@NonNull ViewGroup parent, int viewType);

然后我又看了下作者封裝的這個(gè)方法

image.png

好奇按百度出來(lái)的博客跟了下源碼LayoutInflater源碼，的確如此

image.png

又看了下RecyclerView的ViewHolder，創(chuàng)建ViewHolder的時(shí)候會(huì)傳遞itemView

image.png

問(wèn)題可能是復(fù)用的時(shí)候調(diào)用了onCreateViewHolder，onCreateViewHolder出現(xiàn)神經(jīng)病，認(rèn)為itemView有parent，或者是rv緩存問(wèn)題，或者我分析方向不對(duì)

因?yàn)槲揖蛷?fù)現(xiàn)過(guò)2次，后面就沒(méi)復(fù)現(xiàn)了就按大佬說(shuō)緩存下，原本項(xiàng)目中沒(méi)設(shè)置setOffscreenPageLimit，后面有時(shí)間再研究，可能我比較菜

fragment在viewpager容器里來(lái)回切換，如果沒(méi)有設(shè)置，會(huì)導(dǎo)致重復(fù)實(shí)例化，重復(fù)加載數(shù)據(jù)，
建議在設(shè)置一個(gè)緩存，
解決方式：給page



mViewPager.setOffscreenPageLimit(3);
為什么重復(fù)實(shí)例化會(huì)出現(xiàn)這個(gè)問(wèn)題，現(xiàn)在我的需求就是需要重新刷新這個(gè)fragment，怎么處理？