android - 如何从适配器访问外部 View

Question

我的应用程序中有一个显示内容列表的回收 View 。如果用户订阅了，他们可以继续阅读全部内容，如果没有，则隐藏 recyclerview 并显示订阅布局。

布局文件

  <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:background="@color/light_grey"
   android:orientation="vertical"
   android:weightSum="10"
   tools:layout_editor_absoluteY="25dp">


<!--RECYCLER VIEW-->
<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_marginEnd="10dp"
    android:layout_marginStart="10dp"
    android:layout_marginTop="5dp"
    android:layout_weight="8.3"
    android:padding="2dp"
    android:visibility="gone" />

  <!--SUBSCRIBE TO VIEW CONTENT LAYOUT-->
  <RelativeLayout
    android:id="@+id/rlSubscribeToView"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:gravity="center"
    android:visibility="gone"
    android:layout_margin="10dp"
    android:elevation="48dp"
    android:layout_gravity="center"
    android:layout_weight="8.3">

    <TextView
        android:id="@+id/tvSubscribe"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_centerInParent="true"
        android:textColor="@color/maroon"
        android:text="@string/subscribe_to_view"/>

    <Button
        android:id="@+id/btnSubscribe"
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:layout_marginTop="15dp"
        android:layout_marginStart="20dp"
        android:layout_below="@id/tvSubscribe"
        android:layout_marginEnd="20dp"
        android:text="@string/subscribe"
        android:textColor="@color/white" />

  </RelativeLayout>

和

RecyclerView 适配器

    public void onBindViewHolder(@NonNull final ReadViewholder, final int  position) {

    holder.readMoreButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if (userIsSubscribed) {
                //Launch the next Activity
            } else {
               //Show the subscribe layout
                holder.rlSubscribeToView .setVisibility(View.VISIBLE);

               //Then hide the entire recyvlerView
            }

        }
    });
}

class ReadViewholder extends RecyclerView.ViewHolder {

RelativeLayout rlSubscribeToView;
Button readMoreButton;

ReadViewholder(@NonNull View itemView) {
    super(itemView);

    //Not able to find (rlSubscribeToView ) since its not inside the recyclerview
    rlSubscribeToView = itemView.findViewById(R.id.rlSubscribeToView);
    readMoreButton= itemView.findViewById(R.id.readMoreButton);
  }
}

我如何才能访问订阅布局 (rlSubscribeToView)，它与回收器 View 位于同一布局文件中，并且还在适配器中隐藏整个回收器 View ？

Answer 1

通过一些研究，获得的 2 个回调可以让您引用实际的 RecyclerView，onAttachedToRecyclerView和 onDetachedFromRecycler方法。我的猜测是您正在调用 Adapter 构造函数并传入上下文。如果是这样，请使用以下代码，它将产生您想要的结果。

RelativeLayout rlSubscribeToView;
RecyclerView recyclerView;

public RecyclerAdapter(Context context) {
    this.context = context;
    this.videoItems = videoItems;

    rlSubscribeToView = ((Activity) context).findViewById(R.id.rlSubscribeToView);
}

 @Override
public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
    this.recyclerView = recyclerView;
}

并且在您的 onBindViewHolder 中，您现在可以访问订阅布局

public void onBindViewHolder(@NonNull final ReadViewholder, final int  position) {
 ...
   rlSubscribeToView.setVisibility();
}