关于c#的问题，请问大家如何解决？

做了一个button和一个picturebox，想通过点击button切换picturebox的图片，但是出错了
下面为代码：

using System;
using System.Windows.Forms;

namespace A
{
    class B
    {
        static void Main(string[] args)
        {
            C W=new C();
            W.ShowDialog();
        }
    }
    class C:Form
    {
        public Button button1;
        public PictureBox pictureBox1;
        public C()
        {
            InitializeComponent();
        }
        public void InitializeComponent()
        {
            this.button1.Name="button1";
            this.button1.Size=new Size(60,20);
            this.button1.Location=new Point(100,100);
            this.button1.Text="按钮";
            this.button1.Click+=this.anniu;
            this.Controls.Add(this.button1);
            
            this.pictureBox1.Name="pictureBox1";
            this.pictureBox1.Size=new Size(200,200);
            this.pictureBox1.Location=new Point(300,300);
            this.pictureBox1.Image=Image.FromFile("1.jpg");
            this.Controls.Add(this.pictureBox1);
        }

        public void anniu(object? sender, EventArgs e)
        {
            this.pictureBox1.Image=Image.FromFile("2.jpg");
        }
        
    }
}

下面为报错：

你看看文件路径是否正确，建议使用绝对路径试试