Question

我刚刚创建了一个回收站视图但它没有工作，所以我在getItemCount上放了一个断点，并且没有调用该方法。我从未见过其他任何人都有这个问题，我相信这是非常明显的事情。这是我的代码。

public class SearchAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

private ArrayList<Object> displayList;

public static class ViewHolder extends RecyclerView.ViewHolder {
    public ViewHolder(View v) {
        super(v);
    }
}

public class ErrorSearchItem extends ViewHolder {
    //this is here if there is no other viewholder

    public ErrorSearchItem(View view) {
        super(view);

    }
}

public class HeaderViewHolder extends ViewHolder {


    public HeaderViewHolder(View view) {
        super(view);

    }
}



@Override
public int getItemViewType(int position) {

    return position;
}

public SearchAdapter(ArrayList<Object> displayList) {
    this.displayList = displayList;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    if (displayList.get(viewType) instanceof String){
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.row_search_title, parent, false);
        return new HeaderViewHolder(itemView);
    }
    else{  //this is for if there is an error and no other xml files match
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.row_error_search_item, parent, false);
        return new ErrorSearchItem(itemView);
    }
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

}


@Override
public int getItemCount() {

    return displayList.size();
}

@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);

}

}

编辑：片段代码：

private RecyclerView recyclerView;
private SearchAdapter searchAdapter;

 recyclerView = (RecyclerView) v.findViewById(R.id.recycler_view);

    searchAdapter = new SearchAdapter(categorizedArray);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setAdapter(searchAdapter);

Answer 1

我知道这完全是胡说八道，但对我来说，当我将RecylerView layout_width和layout_height属性从match_parent更改为wrap_content时，问题就解决了。

Answer 2

在应用适配器之前添加16

Answer 3

@Mohammed 的回答帮助我意识到我需要设置一个 LayoutManager，但我很困惑，因为我看过一个包含 RecyclerView 实现的自动生成的项目，但它没有设置布局管理器。

我发现您也可以在 xml 中设置布局管理器：

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layoutManager="LinearLayoutManager"
    >
</androidx.recyclerview.widget.RecyclerView>

Recycler视图不调用getItemCount

3 个答案: