'androidx.recyclerview.widget.RecyclerView.Adapter' 中的 'notifyItemInserted(int)' 无法应用于 '()'

这个错误可能是因为你没有传入要插入的位置参数。`notifyItemInserted` 方法需要一个整数参数，即要插入的位置。你需要在这个方法中传入一个整数参数来指定插入的位置。例如，如果你想在位置 3 插入一个新的项目，你可以这样调用 `notifyItemInserted` 方法：

adapter.notifyItemInserted(3);

请确保你已经确定了要插入的位置，并将其传递给 `notifyItemInserted` 方法。

相关问题

Implements method in Adapter in RecyclerView (androidx.recyclerview.widget)

To implement a custom Adapter in RecyclerView, you need to follow these steps:

1. Create a new class that extends RecyclerView.Adapter. This class will act as the adapter for your RecyclerView.

2. Override the onCreateViewHolder method, which is responsible for creating the ViewHolder objects for each item in the RecyclerView. In this method, you need to inflate the layout for the item and create a new ViewHolder object that holds a reference to the views in the layout.

3. Override the onBindViewHolder method, which is responsible for binding the data to the views in the ViewHolder object. In this method, you need to get the data for the current item and set it to the views in the ViewHolder object.

4. Override the getItemCount method, which returns the total number of items in the RecyclerView.

Here's an example code snippet for implementing a custom Adapter in RecyclerView:

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private List<String> mData;

    public MyAdapter(List<String> data) {
        mData = data;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.my_item_layout, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        String item = mData.get(position);
        holder.mTextView.setText(item);
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mTextView;

        public ViewHolder(View itemView) {
            super(itemView);
            mTextView = itemView.findViewById(R.id.text_view);
        }
    }
}

In this example, the MyAdapter class extends RecyclerView.Adapter and takes a list of strings as data in its constructor. The onCreateViewHolder method inflates the layout for each item from a layout resource file and creates a new ViewHolder object. The onBindViewHolder method sets the text for each item in the RecyclerView. Finally, the getItemCount method returns the total number of items in the RecyclerView.

Note that in this example, the ViewHolder class is defined as a static inner class of the MyAdapter class. This is a common practice to keep the code organized and to avoid memory leaks.

安卓复杂的页面中androidx.appcompat.widget.Toolbar和androidx.recyclerview.widget.RecyclerView 如何让遥控器能够在每一个控件textview buttom 上聚焦焦点的示例demo

在Android中，`androidx.appcompat.widget.Toolbar` 和 `androidx.recyclerview.widget.RecyclerView` 都是常用的组件，通常用于构建应用的头部导航栏和列表部分。为了实现在每个TextView和Button上启用遥控器焦点切换，你需要在它们上设置点击监听器，并处理焦点转移。

首先，确保引入了所需的库：

<dependency>
    <groupId>com.google.android.material</groupId>
    <artifactId>material-components-android</artifactId>
    <!-- Add the appropriate version -->
</dependency>

然后，在Toolbar中添加焦点处理：

// 在Activity或Fragment中
 Toolbar toolbar = findViewById(R.id.toolbar);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        // 当用户点击菜单按钮时，切换焦点到第一个RecyclerView item
        RecyclerView recyclerView = findViewById(R.id.recycler_view);
        if (recyclerView != null && recyclerView.getChildCount() > 0) {
            recyclerView.requestFocus();
            recyclerView.getChildAt(0).requestFocus();
        }
    }
});

对于RecyclerView，需要在Adapter中设置每个ViewHolder的点击事件，并传递焦点到下一个合适的item：

// 在RecyclerView.Adapter中
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            // 确保焦点在合适的位置跳转
            RecyclerView recyclerView = (RecyclerView) view.getParent().getParent(); // 获取当前适配器所在的RecyclerView
            if (position + 1 < recyclerView.getAdapter().getItemCount()) {
                recyclerView.smoothScrollToPosition(position + 1); // 使用平滑滚动效果
                recyclerView.getChildAt(position + 1).requestFocus(); // 赋予下一个item焦点
            } else {
                toolbar.requestFocus(); // 如果到达最后一项，将焦点返回到顶部Toolbar
            }
        }
    });
}

以上代码只是一个基本示例，实际项目中可能还需要考虑滚动状态、连续点击操作以及其他边缘情况的处理。在运行时，请确保已添加权限支持，如`ACTION_FOCUS_CHANGE`，并检查设备是否支持远程输入。