java - 适配器类错误。创建时不得附加 ViewHolder View

Question

我的代码有问题，我在一个 recyclerview 中创建了两个适配器。我将它们放在一个类中，并且我需要此适配器根据某些情况返回一个 Viewholder。

这是我的适配器代码:

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

public List<Task> taskList;
private static final int ITEM_TYPE_PUBLISHED_TASK = 1;
private static final int ITEM_TYPE_ASSIGNED_TASK = 2;

public CurrentUserTaskListAdapter(List<Task> taskList) {
    this.taskList = taskList;
}

public class AssignedTaskViewHolder extends RecyclerView.ViewHolder {
    View mView;

    public TextView tvTagAndDate;
    public TextView tvStatus;

    public AssignedTaskViewHolder(View itemView) {
        super(itemView);
        mView = itemView;

        tvTagAndDate = itemView.findViewById(R.id.tvTagAndDate);
        tvStatus = itemView.findViewById(R.id.tvStatus);
    }
}

public class PublishedTaskViewHolder extends RecyclerView.ViewHolder {
    View mView;

    public TextView tvTagAndDate;
    public TextView tvStatus;

    public PublishedTaskViewHolder(View itemView) {
        super(itemView);
        mView = itemView;

        tvTagAndDate = itemView.findViewById(R.id.tvTagAndDate);
        tvStatus = itemView.findViewById(R.id.tvStatus);
    }
}

    @Override
    public int getItemViewType(int position) {
        if (taskList.get(position).getAssignedTo() == null)
            return ITEM_TYPE_PUBLISHED_TASK;
        else
            return ITEM_TYPE_ASSIGNED_TASK;
    }

@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    LayoutInflater layoutInflater = LayoutInflater.from(viewGroup.getContext());

    if(i == ITEM_TYPE_ASSIGNED_TASK){
        layoutInflater.inflate(R.layout.layout_curent_user_assigned_tasks_item, viewGroup, false);

        return new AssignedTaskViewHolder(viewGroup);
    }
    else if (i == ITEM_TYPE_PUBLISHED_TASK){
        layoutInflater.inflate(R.layout.layout_current_user_pending_tasks, viewGroup, false);

        return new PublishedTaskViewHolder(viewGroup);
    }

    return null;
}

@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
    if(viewHolder instanceof AssignedTaskViewHolder){
        final AssignedTaskViewHolder assignedTaskViewHolder = (AssignedTaskViewHolder) viewHolder;
    }
    else if (viewHolder instanceof PublishedTaskViewHolder) {
        final PublishedTaskViewHolder publishedTaskViewHolder = (PublishedTaskViewHolder) viewHolder;
    }
}

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

我遇到的问题是出现此错误:

java.lang.IllegalStateException: ViewHolder views must not be attached when created. Ensure that you are not passing 'true' to the attachToRoot parameter of LayoutInflater.inflate(..., boolean attachToRoot) at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:6796) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5975) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)....and so on

在 getItemViewType 方法中，我验证列表中的对象是哪种类型。

Answer 1

修复示例中的这部分:

if (i == ITEM_TYPE_ASSIGNED_TASK) {
    View view = layoutInflater.inflate(R.layout.layout_curent_user_assigned_tasks_item, viewGroup, false);

    return new AssignedTaskViewHolder(view);
} else if (i == ITEM_TYPE_PUBLISHED_TASK) {
    View view = layoutInflater.inflate(R.layout.layout_current_user_pending_tasks, viewGroup, false);

    return new PublishedTaskViewHolder(view);
}

问题是您正在将父布局传递给 ViewHolder 的项目布局。祝你好运!