我如何让我的PictureBox在另一个经过它的时候是透明的？

// 创建一个Panel作为PictureBox的父容器
Panel panel = new Panel();
panel.BackColor = Color.Transparent;
panel.Size = new Size(200, 200);

// 创建一个PictureBox并设置透明度
PictureBox pictureBox = new PictureBox();
pictureBox.Image = Image.FromFile("image.png");
pictureBox.SizeMode = PictureBoxSizeMode.StretchImage;
pictureBox.Alpha = 128; // 设置透明度为128

// 将PictureBox添加到Panel中
panel.Controls.Add(pictureBox);

// 处理Panel的绘制事件
panel.Paint += (sender, e) =>
{
    // 设置绘制参数，实现透明效果
    e.Graphics.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceOver;
    e.Graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
    e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
    e.Graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

    // 绘制Panel及其子控件
    panel.DrawToBitmap(e.Graphics, panel.ClientRectangle);
};

// 将Panel添加到窗体中
this.Controls.Add(panel);