如何使用箭头键/WASD键进行PictureBox移动？

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

public class MainForm : Form
{
    private PictureBox pictureBox;
    private int moveSpeed = 5; // 移动速度

    public MainForm()
    {
        pictureBox = new PictureBox();
        pictureBox.Size = new Size(50, 50);
        pictureBox.BackColor = Color.Blue;
        pictureBox.Location = new Point(50, 50);
        this.Controls.Add(pictureBox);

        this.KeyPreview = true; // 允许窗体接收键盘事件
        this.KeyDown += MainForm_KeyDown;
    }

    private void MainForm_KeyDown(object sender, KeyEventArgs e)
    {
        int newX = pictureBox.Location.X;
        int newY = pictureBox.Location.Y;

        switch (e.KeyCode)
        {
            case Keys.Up:
                newY -= moveSpeed;
                break;
            case Keys.Down:
                newY += moveSpeed;
                break;
            case Keys.Left:
                newX -= moveSpeed;
                break;
            case Keys.Right:
                newX += moveSpeed;
                break;
            case Keys.W:
                newY -= moveSpeed;
                break;
            case Keys.S:
                newY += moveSpeed;
                break;
            case Keys.A:
                newX -= moveSpeed;
                break;
            case Keys.D:
                newX += moveSpeed;
                break;
        }

        // 边界检查
        newX = Math.Max(0, Math.Min(this.ClientSize.Width - pictureBox.Width, newX));
        newY = Math.Max(0, Math.Min(this.ClientSize.Height - pictureBox.Height, newY));

        pictureBox.Location = new Point(newX, newY);
    }

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new MainForm());
    }
}