将 RecyclerView 可见性从 Gone 更改为 Visible,在显示新添加的项目之前,会暂时错误地显示先前删除的项目

Ahs*_*fiq 9 android visibility android-recyclerview

背景/背景:

在我的主要活动中,我有一个选项卡布局有两个选项卡。每个选项卡包含两个片段,SearchVehicleFragment 和 VehicleListFragment。

以下是 VehicleListFragment 的布局文件。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".ui.fragments.VehicleListFragment"
    android:orientation="vertical">


    <com.boulevardclan.vvp.ui.recyclerviews.VehicleRecyclerView
        android:id="@+id/rvVehicleList"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <TextView
        android:id="@+id/tvNoSearchedVehicles"
        style="?android:attr/textAppearanceMedium"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:gravity="center"
        android:text="You haven't searched for any vehicles yet." />
</LinearLayout>
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我的 VehicleRecyclerView 的创建与此处提供的 AttractionsRecyclerView 完全一样。这是因为我想为我的 VehicleRecyclerView 实现空状态机制。此外,在初始化期间,我的 VehicleRecyclerView 有setHasFixedSize(true)

public class VehicleRecyclerView extends RecyclerView {
    private View mEmptyView;

    public VehicleRecyclerView(Context context) {
        super(context);
    }

    private AdapterDataObserver mDataObserver = new AdapterDataObserver() {
        @Override
        public void onChanged() {
            super.onChanged();
            updateEmptyView();
        }

        @Override
        public void onItemRangeRemoved(int positionStart, int itemCount) {
            super.onItemRangeRemoved(positionStart, itemCount);
            try{
                updateEmptyView();
            }catch(Exception e){
            //                TODO
            }
        }

        @Override
        public void onItemRangeInserted(int positionStart, int itemCount) {
            super.onItemRangeInserted(positionStart, itemCount);
            updateEmptyView();
        }

        @Override
        public void onItemRangeChanged(int positionStart, int itemCount) {
            super.onItemRangeChanged(positionStart, itemCount);
            updateEmptyView();
        }

        @Override
        public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
            super.onItemRangeMoved(fromPosition, toPosition, itemCount);
            updateEmptyView();
        }
    };

    public VehicleRecyclerView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public VehicleRecyclerView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    /**
     * Designate a view as the empty view. When the backing adapter has no
     * data this view will be made visible and the recycler view hidden.
     *
     */
    public void setEmptyView(View emptyView) {
        mEmptyView = emptyView;
    }

    @Override
    public void setAdapter(RecyclerView.Adapter adapter) {
        if (getAdapter() != null) {
            getAdapter().unregisterAdapterDataObserver(mDataObserver);
        }
        if (adapter != null) {
            adapter.registerAdapterDataObserver(mDataObserver);
        }
        super.setAdapter(adapter);
        updateEmptyView();
    }

    private void updateEmptyView() {
        if (mEmptyView != null && getAdapter() != null) {
            boolean showEmptyView = getAdapter().getItemCount() == 0;
            if(showEmptyView){
                mEmptyView.setVisibility(VISIBLE);
                setVisibility(GONE);
            }else {
                mEmptyView.setVisibility(GONE);
                setVisibility(VISIBLE);
            }
        }
    }
}
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我的 VehicleAdaptersetHasStableIds(true)和 overriden 一样getItemId(position)

public class VehicleAdapter extends RecyclerView.Adapter<VehicleAdapter.VehicleViewHolder> {

    private List<Vehicle> vehicleList = new ArrayList<>();
    private Context mContext;

    public VehicleAdapter(Context context, List<Vehicle> vehicles) {
        vehicleList.addAll(vehicles);
        setHasStableIds(true);
        mContext = context;
    }

    @Override
    public VehicleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new VehicleViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.vehicle_list_item_card_view, parent, false));
    }

    @Override
    public void onBindViewHolder(VehicleViewHolder holder, int position) {
        holder.bind(vehicleList.get(position));
    }

    @Override
    public int getItemCount() {
        return vehicleList.size();
    }

    @Override
    public long getItemId(int position) {
        return vehicleList.get(position).getId();
    }

    public void addVehicle(Vehicle vehicle){
        if(vehicleList != null){
            vehicleList.add(0, vehicle);
            notifyItemInserted(0);
        }
    }

    public void removeVehicle(int position){
        if(vehicleList.get(position).delete()){
            vehicleList.remove(position);
            notifyItemRemoved(position);
        }else {
//            TODO
        }
    }

    public void updateVehicle(Vehicle vehicle, int position){
        vehicleList.set(position, vehicle);
        notifyItemChanged(position);
    }

    class VehicleViewHolder extends RecyclerView.ViewHolder{

        TextView tvRegistrationNumber;
        TextView tvOwnerName;
        TextView tvColor;
        TextView tvOwnerCity;
        TextView tvLookupDate;
        TextView tvManufacturer;
        TextView tvModel;
        TextView tvMakeYear;

        ImageView ivDetail;
        ImageView ivBookmark;
        ImageView ivDelete;

        public VehicleViewHolder(View itemView) {
            super(itemView);

            tvRegistrationNumber = (TextView) itemView.findViewById(R.id.tvRegistrationNumber);
            tvOwnerName = (TextView) itemView.findViewById(R.id.tvOwnerName);
            tvColor = (TextView) itemView.findViewById(R.id.tvColor);
            tvOwnerCity = (TextView) itemView.findViewById(R.id.tvOwnerCity);
            tvLookupDate = (TextView) itemView.findViewById(R.id.tvLookupDate);
            tvManufacturer = (TextView) itemView.findViewById(R.id.tvManufacturer);
            tvModel = (TextView) itemView.findViewById(R.id.tvModel);
            tvMakeYear = (TextView) itemView.findViewById(R.id.tvMakeYear);

            ivDetail = (ImageView) itemView.findViewById(R.id.ivDetail);
            ivBookmark = (ImageView) itemView.findViewById(R.id.ivBookmark);
            ivDelete = (ImageView) itemView.findViewById(R.id.ivDelete);
        }

        void setOwnerName(String ownerName){
            tvOwnerName.setText(ownerName);
        }
        void setColor(String color){
            tvColor.setText(color);
        }
        void setOwnerCity(String ownerCity){
            tvOwnerCity.setText(ownerCity);
        }
        void setLookupDate(String lookupDate){
            tvLookupDate.setText(lookupDate);
        }
        void setManufacturer(String manufacturer){
            tvManufacturer.setText(manufacturer);
        }
        void setMakeYear(int makeYear){
            tvMakeYear.setText(String.format(Locale.getDefault(),"%s",makeYear));
        }
        void setModel(String model){
            tvModel.setText(model);
        }
        void setBookmarked(boolean isBookmarked){
            ivBookmark.setImageDrawable(ViewUtils.getDrawable(mContext, (isBookmarked ? R.drawable.ic_favorite_black_24dp: R.drawable.ic_favorite_border_black_24dp)));
        }

        void bind(final Vehicle vehicle){
            tvRegistrationNumber.setText(vehicle.getRegistrationNumber());
            setOwnerName(vehicle.getOwnerName());
            setColor(vehicle.getColor());
            setOwnerCity(vehicle.getOwnerCity());
            setLookupDate(DateTimeUtils.getPKTDateTime(vehicle.getModifiedAt()));
            setManufacturer(vehicle.getManufacturer());
            setModel(vehicle.getMakeType());
            setMakeYear(vehicle.getMakeYear());
            setBookmarked(vehicle.isBookmarked());
            setupClickListeners(vehicle);
        }

        private void setupClickListeners(final Vehicle vehicle) {
            ivDelete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    new MaterialDialog.Builder(mContext)
                            .title(R.string.confirm_delete_vehicle_heading)
                            .content(R.string.confirm_delete_vehicle_label)
                            .positiveText(R.string.confirm_response_yes)
                            .negativeText(R.string.confirm_response_cancel)
                            .stackingBehavior(StackingBehavior.ALWAYS)
                            .onPositive(new MaterialDialog.SingleButtonCallback() {
                                @Override
                                public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {
                                    if(getAdapterPosition() != RecyclerView.NO_POSITION){
                                        removeVehicle(getAdapterPosition());
                                    }
                                }
                            })
                            .show();
                }
            });
        }
    }
}
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问题:

当 recyclerview 中没有项目并且我通过 向 recyclerview 添加一个或多个新项目时notifyItemInserted(0),一切正常。但是当 recyclerview 中只有一个项目时,我通过删除该项目notifyItemRemoved(position),现在通过添加一个新项目到 recyclerview via notifyItemInserted(0),有一个过渡/动画效果,在隐藏 emptyView 后,recyclerview 显示为之前删除的项目几分之一秒,然后新添加的项目淡入视口。

因此,这是应该遵循的“理想”事件序列:

  1. [工作正常]我删除了回收站视图中的最后一项。recyclerview 的可见性更改为 GONE,emptyView (TextView) 可见性更改为 VISIBLE。
  2. [工作正常]然后,我向回收站视图添加了一个新项目。emptyView 的可见性更改为 GONE。
  3. [未按预期工作] recyclerview 的可见性应更改为 VISIBLE 并且它应仅包含一项,即新添加的项目 [未按预期工作] 相反,有一个 flickr/blink,其中显示了只有以前存在的项目的 recyclerview几分之一秒,然后该项目通过淡入(?)过渡由新添加的项目替换。

更新:您可以在此处查看问题:https : //media.giphy.com/media/l0IydcuJDAqPNlmla/giphy.gif

我期待着一种方法来摆脱这种在很短的时间内显示旧项目/recyclerview 状态的 flickr/blink 效果。


我尝试过的:

RecyclerView.ItemAnimator animator = mVehicleListRV.getItemAnimator();
if (animator instanceof SimpleItemAnimator) {
    ((SimpleItemAnimator) animator).setSupportsChangeAnimations(false);
}
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免责声明:

我是 Android 开发的新手,并且在这个问题上困了好几个小时。寻求来自SO的伟大思想家的帮助/指点,以畅通无阻。请容忍我有限的知识。

Anu*_*hav 0

您可以使用可见性 INVISIBLE 而不是 GONE,在这种情况下,即使适配器不可见,也会调用 onBindViewHolder get。