Android水平recyclerview自动滚动到中心

Question

我希望我的水平回收器视图在设置适配器后始终显示第一项，而不是滚动到中心项。我怎样才能做到这一点？

这是我的 Recommendation.xml 文件：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/img"
        android:layout_marginLeft="10dp"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_marginTop="5dp"
        android:layout_marginBottom="5dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/zone"
        android:textColor="@color/colorPrimary"
        android:textSize="18sp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintStart_toStartOf="@+id/xyz"
        app:layout_constraintEnd_toEndOf="@+id/xyz"
        android:layout_marginTop="3dp"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/xyz"
        android:gravity="center"
        android:textSize="16sp"
        android:layout_marginLeft="15dp"
        app:layout_constraintTop_toBottomOf="@id/zone"
        android:layout_marginTop="5dp"
        app:layout_constraintStart_toEndOf="@id/img"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/day"
        android:gravity="center"
        android:textSize="16sp"
        app:layout_constraintTop_toBottomOf="@id/xyz"
        app:layout_constraintStart_toStartOf="@id/xyz"
        app:layout_constraintEnd_toEndOf="@id/xyz"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="6dp"/>


</androidx.constraintlayout.widget.ConstraintLayout>

这是我的适配器类：

class recom_adapter extends RecyclerView.Adapter<recom_adapter.ViewHolder> {
    private List<saved_zone> zoneList;
    private Context context;
    public static PrefConfig prefConfig;

    public recom_adapter(List<saved_zone> zoneList, Context context) {
        this.zoneList = zoneList;
        this.context = context;
    }

    @NonNull
    @Override
    public recom_adapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.recommendation,parent,false);
        return new recom_adapter.ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull recom_adapter.ViewHolder holder, int position) {
        saved_zone sz = zoneList.get(position);
        Glide.with(context).load(sz.getImageUrl).into(holder.img);
        
        holder.xyz.setText(sz.getXYZ());
        holder.day.setText(sz.getDate());
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder{
        private ImageView img;
        TextView zone, xyz, day;

        public ViewHolder(View itemView) {
            super(itemView);
            img = itemView.findViewById(R.id.img);

            zone = itemView.findViewById(R.id.zone);
            xyz = itemView.findViewById(R.id.xyz);
            day = itemView.findViewById(R.id.day);
        }
    }
}

这就是我在我的 mainActivity 中的适配器中设置 recyclerView 的方式：

recomm_recycler.setLayoutManager(new LinearLayoutManager(getActivity(),LinearLayoutManager.HORIZONTAL, true));
                recomData = response.body();
                recom_adapter = new recom_adapter(recomData, getActivity());
                recomm_recycler.setAdapter(recom_adapter);

Answer 1

recomm_recycler.setLayoutManager(new LinearLayoutManager(getActivity(),LinearLayoutManager.HORIZONTAL, true));

你上面那行有问题。

将true 更改为false

新代码

recomm_recycler.setLayoutManager(new LinearLayoutManager(getActivity(),LinearLayoutManager.HORIZONTAL, false));

Answer 2

我在垂直回收站视图中遇到了类似的问题。在我的情况下添加

    android:focusableInTouchMode="true"

RecyclerView 的父母帮了我。

Answer 3

在你的主要 XML 父布局中试试这个

XML：

android:descendantFocusability="blocksDescendants"

Java：

listItem.setDescendantFocusability(FOCUS_BLOCK_DESCENDANTS);