如何在c#中为流布局面板创建自定义滚动按钮

using System;
using System.Drawing;
using System.Windows.Forms;

public class CustomFlowLayoutPanel : Panel
{
    private Button scrollUpButton;
    private Button scrollDownButton;

    public CustomFlowLayoutPanel()
    {
        // 初始化滚动按钮
        scrollUpButton = new Button();
        scrollUpButton.Text = "▲";
        scrollUpButton.Click += ScrollUpButton_Click;

        scrollDownButton = new Button();
        scrollDownButton.Text = "▼";
        scrollDownButton.Click += ScrollDownButton_Click;

        // 添加滚动按钮到面板
        Controls.Add(scrollUpButton);
        Controls.Add(scrollDownButton);
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        // 绘制滚动按钮的外观
        Graphics g = e.Graphics;
        g.FillRectangle(Brushes.White, scrollUpButton.Bounds);
        g.FillRectangle(Brushes.White, scrollDownButton.Bounds);
        g.DrawRectangle(Pens.Black, scrollUpButton.Bounds);
        g.DrawRectangle(Pens.Black, scrollDownButton.Bounds);
    }

    private void ScrollUpButton_Click(object sender, EventArgs e)
    {
        // 向上滚动
        VerticalScroll.Value -= VerticalScroll.SmallChange;
    }

    private void ScrollDownButton_Click(object sender, EventArgs e)
    {
        // 向下滚动
        VerticalScroll.Value += VerticalScroll.SmallChange;
    }
}

// 在窗体中使用CustomFlowLayoutPanel
public class MainForm : Form
{
    public MainForm()
    {
        // 创建自定义流布局面板
        CustomFlowLayoutPanel customFlowLayoutPanel = new CustomFlowLayoutPanel();
        customFlowLayoutPanel.Dock = DockStyle.Fill;

        // 添加一些控件到自定义流布局面板
        for (int i = 0; i < 50; i++)
        {
            Button button = new Button();
            button.Text = "Button " + (i + 1);
            customFlowLayoutPanel.Controls.Add(button);
        }

        // 添加自定义流布局面板到窗体
        Controls.Add(customFlowLayoutPanel);
    }
}

// 应用程序入口点
public class Program
{
    [STAThread]
    public static void Main()
    {
        Application.Run(new MainForm());
    }
}