本文介绍了如何使用 RecyclerView.State 保存 RecyclerView 的滚动位置?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个关于 Android 的 RecyclerView.State 的问题.
I have a question about Android's RecyclerView.State.
我正在使用 RecyclerView,如何使用 RecyclerView.State 并将其绑定?
I am using a RecyclerView, how could I use and bind it with RecyclerView.State?
我的目的是保存 RecyclerView 的滚动位置.
推荐答案你打算如何使用 RecyclerView.State 保存上次保存的位置?
How do you plan to save last saved position with RecyclerView.State?
您始终可以依靠良好的保存状态.扩展 RecyclerView 并覆盖 onSaveInstanceState() 和 onRestoreInstanceState():
You can always rely on ol' good save state. Extend RecyclerView and override onSaveInstanceState() and onRestoreInstanceState():
@Override protected Parcelable onSaveInstanceState() { Parcelable superState = super.onSaveInstanceState(); LayoutManager layoutManager = getLayoutManager(); if(layoutManager != null && layoutManager instanceof LinearLayoutManager){ mScrollPosition = ((LinearLayoutManager) layoutManager).findFirstVisibleItemPosition(); } SavedState newState = new SavedState(superState); newState.mScrollPosition = mScrollPosition; return newState; } @Override protected void onRestoreInstanceState(Parcelable state) { super.onRestoreInstanceState(state); if(state != null && state instanceof SavedState){ mScrollPosition = ((SavedState) state).mScrollPosition; LayoutManager layoutManager = getLayoutManager(); if(layoutManager != null){ int count = layoutManager.getItemCount(); if(mScrollPosition != RecyclerView.NO_POSITION && mScrollPosition < count){ layoutManager.scrollToPosition(mScrollPosition); } } } } static class SavedState extends android.view.View.BaseSavedState { public int mScrollPosition; SavedState(Parcel in) { super(in); mScrollPosition = in.readInt(); } SavedState(Parcelable superState) { super(superState); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeInt(mScrollPosition); } public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { @Override public SavedState createFromParcel(Parcel in) { return new SavedState(in); } @Override public SavedState[] newArray(int size) { return new SavedState[size]; } }; }更多推荐
如何使用 RecyclerView.State 保存 RecyclerView 的滚动位置?
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