我正在尝试使用Recyclerview制作可扩展的CardView。我能够看到列表，但是当我单击某些卡片视图并滚动时，其他一些视图也会展开。就像当我单击位置"0"并滚动时，位置"17"也会展开。
这是我的代码：
我chapter_cardview.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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="wrap_content">
<android.support.v7.widget.CardView
android:id="@+id/cv"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="4dp"
android:layout_marginEnd="4dp"
android:layout_marginLeft="4dp"
android:layout_marginRight="4dp"
android:layout_marginStart="4dp"
android:layout_marginTop="4dp"
android:theme="@style/Theme.AppCompat.Light.DarkActionBar"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/chapter_detail"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:text="TextView"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/chapter_title" />
<TextView
android:id="@+id/chapter_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="4dp"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="4dp"
android:text="TextView"
app:layout_constraintBottom_toTopOf="@+id/chapter_detail"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
</android.support.v7.widget.CardView>
</android.support.constraint.ConstraintLayout>我的适配器.java
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
static private List<chapter_title>mDataset;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public CardView mCardView;
private TextView mchapter_tile;
private TextView mchapter_detail;
public ViewHolder(View itemview) {
super(itemview);
mCardView = itemView.findViewById(R.id.cv);
mchapter_tile = itemview.findViewById(R.id.chapter_title);
mchapter_detail = itemview.findViewById(R.id.chapter_detail);
}
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(List<chapter_title> myDataset) {
mDataset = myDataset;
}
// Create new views (invoked by the layout manager)
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
ViewHolder vh = null;
View view = (View) LayoutInflater.from(parent.getContext())
.inflate(R.layout.chapter_cardview, parent, false);
vh = new ViewHolder(view);
Log.e("viewType: ", ""+viewType);
if (viewType == 1)
vh.mchapter_detail.setVisibility(View.VISIBLE);
else
vh.mchapter_detail.setVisibility(View.GONE);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.mchapter_tile.setText(mDataset.get(position).title);
holder.mCardView.setTag(position);
holder.mCardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int position = (Integer)v.getTag();
boolean isShown = MyAdapter.mDataset.get(position).isExpanded;
Log.e("Clicked on:", ""+ position);
if(isShown)
{
MyAdapter.mDataset.get(position).isExpanded = false;
((CardView)v).findViewById(R.id.chapter_detail).setVisibility(View.GONE);
}
else
{
((CardView)v).findViewById(R.id.chapter_detail).setVisibility(View.VISIBLE);
MyAdapter.mDataset.get(position).isExpanded = true;
}
}
});
}
@Override
public int getItemViewType(int position)
{
// Log.e("getItemType, position", position+"");
if(mDataset.get(position).isExpanded==true)
return 1;
else
return 0;
}
// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
// Log.e("list size", mDataset.size()+"");
return mDataset.size()-50;
}
}
`
适配器文件中有一些更改。在绑定视图时，我们首先根据我们设置的结果检查是否扩展视图的可见性。下面是适配器的代码。
公共类 MyAdapter 扩展了 RecyclerView.Adapter { 私有列表 mDataset;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public CardView mCardView;
private TextView mchapter_tile;
private TextView mchapter_detail;
public ViewHolder(View itemview) {
super(itemview);
mCardView = itemView.findViewById(R.id.cv);
mchapter_tile = itemview.findViewById(R.id.chapter_title);
mchapter_detail = itemview.findViewById(R.id.chapter_detail);
}
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(List<chapter_title> myDataset) {
mDataset = myDataset;
}
// Create new views (invoked by the layout manager)
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
ViewHolder vh = null;
View view = (View) LayoutInflater.from(parent.getContext())
.inflate(R.layout.stack_question_2, parent, false);
vh = new ViewHolder(view);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
final chapter_title chapter_title = mDataset.get(position);
holder.mchapter_tile.setText(chapter_title.title);
holder.mCardView.setTag(position);
if (chapter_title.isExpanded)
holder.mchapter_detail.setVisibility(View.VISIBLE);
else
holder.mchapter_detail.setVisibility(View.GONE);
holder.mCardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(mDataset.get(position).isExpanded)
{
mDataset.get(position).isExpanded = false;
((CardView)v).findViewById(R.id.chapter_detail).setVisibility(View.GONE);
}
else
{
((CardView)v).findViewById(R.id.chapter_detail).setVisibility(View.VISIBLE);
mDataset.get(position).isExpanded = true;
}
//notifyDataSetChanged();
notifyItemChanged(position);
}
});
}
@Override
public int getItemViewType(int position)
{
// Log.e("getItemType, position", position+"");
if(mDataset.get(position).isExpanded==true)
return 1;
else
return 0;
}
// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
// Log.e("list size", mDataset.size()+"");
return mDataset.size();
}
}
希望有帮助。