下面的代码不是伪代码。我已经测试过了，它对我很有效。

我想在我的recyclerview中创建一个headerview，然后在用户可以点击的标题下面显示一个图片列表。

我在我的代码中使用了一些开关，不知道这是否是最有效的方法，所以请随意给出您的评论:

   public class ViewHolder extends RecyclerView.ViewHolder{

        //These are the general elements in the RecyclerView
        public TextView place;
        public ImageView pics;

        //This is the Header on the Recycler (viewType = 0)
        public TextView name, description;

        //This constructor would switch what to findViewBy according to the type of viewType
        public ViewHolder(View v, int viewType) {
            super(v);
            if (viewType == 0) {
                name = (TextView) v.findViewById(R.id.name);
                decsription = (TextView) v.findViewById(R.id.description);
            } else if (viewType == 1) {
                place = (TextView) v.findViewById(R.id.place);
                pics = (ImageView) v.findViewById(R.id.pics);
            }
        }
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent,
                                         int viewType)
    {
        View v;
        ViewHolder vh;
        // create a new view
        switch (viewType) {
            case 0: //This would be the header view in my Recycler
                v = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.recyclerview_welcome, parent, false);
                vh = new ViewHolder(v,viewType);
                return  vh;
            default: //This would be the normal list with the pictures of the places in the world
                v = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.recyclerview_picture, parent, false);
                vh = new ViewHolder(v, viewType);
                v.setOnClickListener(new View.OnClickListener(){

                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent(mContext, nextActivity.class);
                        intent.putExtra("ListNo",mRecyclerView.getChildPosition(v));
                        mContext.startActivity(intent);
                    }
                });
                return vh;
        }
    }

    //Overridden so that I can display custom rows in the recyclerview
    @Override
    public int getItemViewType(int position) {
        int viewType = 1; //Default is 1
        if (position == 0) viewType = 0; //If zero, it will be a header view
        return viewType;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        //position == 0 means it's the info header view on the Recycler
        if (position == 0) {
            holder.name.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(mContext,"name clicked", Toast.LENGTH_SHORT).show();
                }
            });
            holder.description.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(mContext,"description clicked", Toast.LENGTH_SHORT).show();
                }
            });
            //This means it is beyond the headerview now as it is no longer 0. For testing purposes, I'm alternating between two pics for now
        } else if (position > 0) {
           holder.place.setText(mDataset[position]);
            if (position % 2 == 0) {
               holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic1));
            }
            if (position % 2 == 1) {
                holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic2));
            }
        }
    }

如果有人有兴趣看看用Kotlin编写的超级简单的解决方案，请查看我刚刚创建的博客文章。博客中的例子是基于创建Sectioned RecyclerView的:

https://brona.blog/2020/06/sectioned-recyclerview-in-three-steps/

是的，这是可能的。只需实现getItemViewType()，并照顾onCreateViewHolder()中的viewType参数。

所以你可以这样做:

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    class ViewHolder0 extends RecyclerView.ViewHolder {
        ...
        public ViewHolder0(View itemView){
        ...
        }
    }

    class ViewHolder2 extends RecyclerView.ViewHolder {
        ...
        public ViewHolder2(View itemView){
        ...
    }

    @Override
    public int getItemViewType(int position) {
        // Just as an example, return 0 or 2 depending on position
        // Note that unlike in ListView adapters, types don't have to be contiguous
        return position % 2 * 2;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
         switch (viewType) {
             case 0: return new ViewHolder0(...);
             case 2: return new ViewHolder2(...);
             ...
         }
    }

    @Override
    public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
        switch (holder.getItemViewType()) {
            case 0:
                ViewHolder0 viewHolder0 = (ViewHolder0)holder;
                ...
                break;

            case 2:
                ViewHolder2 viewHolder2 = (ViewHolder2)holder;
                ...
                break;
        }
    }
}

下面是一个完整的示例，展示了一个具有两种类型的RecyclerView，视图类型由对象决定。

类模型

open class RecyclerViewItem
class SectionItem(val title: String) : RecyclerViewItem()
class ContentItem(val name: String, val number: Int) : RecyclerViewItem()

适配器代码

const val VIEW_TYPE_SECTION = 1
const val VIEW_TYPE_ITEM = 2

class UserAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    var data = listOf<RecyclerViewItem>()

    override fun getItemViewType(position: Int): Int {
        if (data[position] is SectionItem) {
            return VIEW_TYPE_SECTION
        }
        return VIEW_TYPE_ITEM
    }

    override fun getItemCount(): Int {
        return data.size
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        if (viewType == VIEW_TYPE_SECTION) {
            return SectionViewHolder(
                LayoutInflater.from(parent.context).inflate(R.layout.item_user_section, parent, false)
            )
        }
        return ContentViewHolder(
            LayoutInflater.from(parent.context).inflate(R.layout.item_user_content, parent, false)
        )
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        val item = data[position]
        if (holder is SectionViewHolder && item is SectionItem) {
            holder.bind(item)
        }
        if (holder is ContentViewHolder && item is ContentItem) {
            holder.bind(item)
        }
    }

    internal inner class SectionViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(item: SectionItem) {
            itemView.text_section.text = item.title
        }
    }

    internal inner class ContentViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(item: ContentItem) {
            itemView.text_name.text = item.name
            itemView.text_number.text = item.number.toString()
        }
    }
}

item_user_section.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/text_section"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#eee"
    android:padding="16dp" />

item_user_content.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="32dp">

    <TextView
        android:id="@+id/text_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:text="Name" />

    <TextView
        android:id="@+id/text_number"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

示例使用

val dataSet = arrayListOf<RecyclerViewItem>(
    SectionItem("A1"),
    ContentItem("11", 11),
    ContentItem("12", 12),
    ContentItem("13", 13),

    SectionItem("A2"),
    ContentItem("21", 21),
    ContentItem("22", 22),

    SectionItem("A3"),
    ContentItem("31", 31),
    ContentItem("32", 32),
    ContentItem("33", 33),
    ContentItem("33", 34),
)

recyclerAdapter.data = dataSet
recyclerAdapter.notifyDataSetChanged()

我推荐汉内斯·多夫曼的这个图书馆。它将所有与特定视图类型相关的逻辑封装在一个名为“AdapterDelegate”的单独对象中。

https://github.com/sockeqwe/AdapterDelegates

public class CatAdapterDelegate extends AdapterDelegate<List<Animal>> {

  private LayoutInflater inflater;

  public CatAdapterDelegate(Activity activity) {
    inflater = activity.getLayoutInflater();
  }

  @Override public boolean isForViewType(@NonNull List<Animal> items, int position) {
    return items.get(position) instanceof Cat;
  }

  @NonNull @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
    return new CatViewHolder(inflater.inflate(R.layout.item_cat, parent, false));
  }

  @Override public void onBindViewHolder(@NonNull List<Animal> items, int position,
      @NonNull RecyclerView.ViewHolder holder, @Nullable List<Object> payloads) {

    CatViewHolder vh = (CatViewHolder) holder;
    Cat cat = (Cat) items.get(position);

    vh.name.setText(cat.getName());
  }

  static class CatViewHolder extends RecyclerView.ViewHolder {

    public TextView name;

    public CatViewHolder(View itemView) {
      super(itemView);
      name = (TextView) itemView.findViewById(R.id.name);
    }
  }
}

public class AnimalAdapter extends ListDelegationAdapter<List<Animal>> {

  public AnimalAdapter(Activity activity, List<Animal> items) {

    // DelegatesManager is a protected Field in ListDelegationAdapter
    delegatesManager.addDelegate(new CatAdapterDelegate(activity))
                    .addDelegate(new DogAdapterDelegate(activity))
                    .addDelegate(new GeckoAdapterDelegate(activity))
                    .addDelegate(23, new SnakeAdapterDelegate(activity));

    // Set the items from super class.
    setItems(items);
  }
}

遵循Anton的解决方案，我想出了这个ViewHolder，它持有/处理/委托不同类型的布局。

但是我不确定当回收视图的ViewHolder不是数据滚入的类型时，替换新的布局是否会工作。

所以基本上, onCreateViewHolder(ViewGroup父视图，int viewType)只在需要新的视图布局时调用;

getItemViewType(int position)将为viewType调用;

onBindViewHolder(ViewHolder holder, int position)总是在回收视图时被调用(新数据被引入并尝试与ViewHolder一起显示)。

当onBindViewHolder被调用时，它需要被放在正确的视图布局中并更新ViewHolder。

public int getItemViewType(int position) {
    TypedData data = mDataSource.get(position);
    return data.type;
}

public ViewHolder onCreateViewHolder(ViewGroup parent,
    int viewType) {
    return ViewHolder.makeViewHolder(parent, viewType);
}

public void onBindViewHolder(ViewHolder holder,
    int position) {
    TypedData data = mDataSource.get(position);
    holder.updateData(data);
}

///
public static class ViewHolder extends
    RecyclerView.ViewHolder {

    ViewGroup mParentViewGroup;
    View mCurrentViewThisViewHolderIsFor;
    int mDataType;

    public TypeOneViewHolder mTypeOneViewHolder;
    public TypeTwoViewHolder mTypeTwoViewHolder;

    static ViewHolder makeViewHolder(ViewGroup vwGrp,
        int dataType) {
        View v = getLayoutView(vwGrp, dataType);
        return new ViewHolder(vwGrp, v, viewType);
    }

    static View getLayoutView(ViewGroup vwGrp,
        int dataType) {
        int layoutId = getLayoutId(dataType);
        return LayoutInflater.from(vwGrp.getContext())
                             .inflate(layoutId, null);
    }

    static int getLayoutId(int dataType) {
        if (dataType == TYPE_ONE) {
            return R.layout.type_one_layout;
        } else if (dataType == TYPE_TWO) {
            return R.layout.type_two_layout;
        }
    }

    public ViewHolder(ViewGroup vwGrp, View v,
        int dataType) {
        super(v);
        mDataType = dataType;
        mParentViewGroup = vwGrp;
        mCurrentViewThisViewHolderIsFor = v;

        if (data.type == TYPE_ONE) {
            mTypeOneViewHolder = new TypeOneViewHolder(v);
        } else if (data.type == TYPE_TWO) {
            mTypeTwoViewHolder = new TypeTwoViewHolder(v);
        }
    }

    public void updateData(TypeData data) {
        mDataType = data.type;
        if (data.type == TYPE_ONE) {
            mTypeTwoViewHolder = null;
            if (mTypeOneViewHolder == null) {
                View newView = getLayoutView(mParentViewGroup,
                               data.type);

                /**
                 *  How can I replace a new view with
                    the view in the parent
                    view container?
                 */
                replaceView(mCurrentViewThisViewHolderIsFor,
                            newView);
                mCurrentViewThisViewHolderIsFor = newView;

                mTypeOneViewHolder =
                    new TypeOneViewHolder(newView);
            }
            mTypeOneViewHolder.updateDataTypeOne(data);

        } else if (data.type == TYPE_TWO){
            mTypeOneViewHolder = null;
            if (mTypeTwoViewHolder == null) {
                View newView = getLayoutView(mParentViewGroup,
                               data.type);

                /**
                 *  How can I replace a new view with
                    the view in the parent view
                    container?
                 */
                replaceView(mCurrentViewThisViewHolderIsFor,
                            newView);
                mCurrentViewThisViewHolderIsFor = newView;

                mTypeTwoViewHolder =
                    new TypeTwoViewHolder(newView);
            }
            mTypeTwoViewHolder.updateDataTypeOne(data);
        }
    }
}

public static void replaceView(View currentView,
    View newView) {
    ViewGroup parent = (ViewGroup)currentView.getParent();
    if(parent == null) {
        return;
    }
    final int index = parent.indexOfChild(currentView);
    parent.removeView(currentView);
    parent.addView(newView, index);
}

ViewHolder有成员mItemViewType来保存视图。

它看起来像在onBindViewHolder(ViewHolder holder, int position)中传递进来的ViewHolder已经通过查看getItemViewType(int position)来获取(或创建)，以确保它是匹配的，所以它可能不需要担心ViewHolder的类型不匹配数据[position]的类型。

看起来循环ViewHolder是由类型选择的，所以这里没有战士。

构建一个RecyclerView LayoutManager -第1部分回答了这个问题。

它像这样得到循环ViewHolder:

holder = getRecycledViewPool().getRecycledView(mAdapter.getItemViewType(offsetPosition));

如果没有找到正确类型的recycle ViewHolder，也可以创建一个新的。

public ViewHolder getRecycledView(int viewType) {
        final ArrayList<ViewHolder> scrapHeap = mScrap.get(viewType);
        if (scrapHeap != null && !scrapHeap.isEmpty()) {
            final int index = scrapHeap.size() - 1;
            final ViewHolder scrap = scrapHeap.get(index);
            scrapHeap.remove(index);
            return scrap;
        }
        return null;
    }

View getViewForPosition(int position, boolean dryRun) {
    ......

    if (holder == null) {
            final int offsetPosition = mAdapterHelper.findPositionOffset(position);
            if (offsetPosition < 0 || offsetPosition >= mAdapter.getItemCount()) {
                throw new IndexOutOfBoundsException("Inconsistency detected. Invalid item "
                        + "position " + position + "(offset:" + offsetPosition + ")."
                        + "state:" + mState.getItemCount());
            }

            final int type = mAdapter.getItemViewType(offsetPosition);
            // 2) Find from scrap via stable ids, if exists
            if (mAdapter.hasStableIds()) {
                holder = getScrapViewForId(mAdapter.getItemId(offsetPosition), type, dryRun);
                if (holder != null) {
                    // update position
                    holder.mPosition = offsetPosition;
                    fromScrap = true;
                }
            }
            if (holder == null && mViewCacheExtension != null) {
                // We are NOT sending the offsetPosition because LayoutManager does not
                // know it.
                final View view = mViewCacheExtension
                        .getViewForPositionAndType(this, position, type);
                if (view != null) {
                    holder = getChildViewHolder(view);
                    if (holder == null) {
                        throw new IllegalArgumentException("getViewForPositionAndType returned"
                                + " a view which does not have a ViewHolder");
                    } else if (holder.shouldIgnore()) {
                        throw new IllegalArgumentException("getViewForPositionAndType returned"
                                + " a view that is ignored. You must call stopIgnoring before"
                                + " returning this view.");
                    }
                }
            }
            if (holder == null) { // fallback to recycler
                // try recycler.
                // Head to the shared pool.
                if (DEBUG) {
                    Log.d(TAG, "getViewForPosition(" + position + ") fetching from shared "
                            + "pool");
                }
                holder = getRecycledViewPool()
                        .getRecycledView(mAdapter.getItemViewType(offsetPosition));
                if (holder != null) {
                    holder.resetInternal();
                    if (FORCE_INVALIDATE_DISPLAY_LIST) {
                        invalidateDisplayListInt(holder);
                    }
                }
            }
            if (holder == null) {
                holder = mAdapter.createViewHolder(RecyclerView.this,
                        mAdapter.getItemViewType(offsetPosition));
                if (DEBUG) {
                    Log.d(TAG, "getViewForPosition created new ViewHolder");
                }
            }
        }
        boolean bound = false;
        if (mState.isPreLayout() && holder.isBound()) {
            // do not update unless we absolutely have to.
            holder.mPreLayoutPosition = position;
        } else if (!holder.isBound() || holder.needsUpdate() || holder.isInvalid()) {
            if (DEBUG && holder.isRemoved()) {
                throw new IllegalStateException("Removed holder should be bound and it should"
                        + " come here only in pre-layout. Holder: " + holder);
            }
            final int offsetPosition = mAdapterHelper.findPositionOffset(position);
            mAdapter.bindViewHolder(holder, offsetPosition);
            attachAccessibilityDelegate(holder.itemView);
            bound = true;
            if (mState.isPreLayout()) {
                holder.mPreLayoutPosition = position;
            }
        }

        final ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();
        final LayoutParams rvLayoutParams;
        if (lp == null) {
            rvLayoutParams = (LayoutParams) generateDefaultLayoutParams();
            holder.itemView.setLayoutParams(rvLayoutParams);
        } else if (!checkLayoutParams(lp)) {
            rvLayoutParams = (LayoutParams) generateLayoutParams(lp);
            holder.itemView.setLayoutParams(rvLayoutParams);
        } else {
            rvLayoutParams = (LayoutParams) lp;
        }
        rvLayoutParams.mViewHolder = holder;
        rvLayoutParams.mPendingInvalidate = fromScrap && bound;
        return holder.itemView;
}