Question

我在下面有一个RecyclerView.Adapter。适配器在没有ItemDiscussionListHeaderBinding的情况下工作正常，但是一旦添加了它，使用两个视图类型，我得到了一个Java.lang.RuntimeException：视图标签在视图上是不正确的：null。为什么会这样？

在我的Adapter.java中：

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    switch (viewType) {
        case BODY:
            ItemDiscussionListBodyBinding bodyBinding = DataBindingUtil.inflate(inflater, R.layout.item_discussion_list_body, parent, false);
            return new DiscussionListItemBodyViewHolder(bodyBinding);
        case HEADER:
            ItemDiscussionListHeaderBinding headerBinding = DataBindingUtil.inflate(inflater, R.layout.item_discussion_list_header, parent, false);
            return new DiscussionListItemHeaderViewHolder(headerBinding);
    }
    return null;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    Discussion discussion = mDiscussions.get(position);
    switch (holder.getItemViewType()) {
        case BODY:
            ((DiscussionListItemBodyViewHolder) holder).bind(discussion);
            break;
        case HEADER:
            ((DiscussionListItemHeaderViewHolder) holder).setHeader("My Discussions");
            break;
    }
}

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

@Override
public int getItemViewType(int position) {
    if (position == 0) {
        return HEADER;
    }
    return BODY;
}

在我的两个观看者中：

class DiscussionListItemBodyViewHolder extends RecyclerView.ViewHolder {
    private ItemDiscussionListBodyBinding mBinding;

    DiscussionListItemBodyViewHolder(ItemDiscussionListBodyBinding binding) {
        super(binding.getRoot());
        mBinding = binding;
    }

    void bind(Discussion discussion) { // do whatever }


class DiscussionListItemHeaderViewHolder extends RecyclerView.ViewHolder {
    private ItemDiscussionListHeaderBinding mBinding;

    DiscussionListItemHeaderViewHolder(ItemDiscussionListHeaderBinding binding) {
        super(binding.getRoot());
        mBinding = binding;
    }

    void setHeader(String header) { // do whatever }

我已将错误缩小到标题绑定，而不是正文绑定，这里是xml：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:background="@color/lighter_gray"
    android:paddingBottom="8dp"
    android:paddingLeft="14dp"
    android:paddingRight="14dp"
    android:paddingTop="8dp">

    <TextView
        android:id="@+id/item_discussion_list_header_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:text="Classes" />
</LinearLayout>

为什么我得到一个Java.lang.RuntimeException：view标签在视图上是不正确的：null

0 个答案: