我在窗体上端有一系列图片的缩略图，当鼠标放在某个缩略图片上时，这个图片从窗体上端逐渐放大并显示在窗体中央。

我当时是这么做的
        void PictureBox1MouseEnter(object sender, System.EventArgs e)
        {
            this.pictureBox1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.pictureBox1.Height = 600;
            this.pictureBox1.Width = 800;
        }
        
        void PictureBox1MouseLeave(object sender, System.EventArgs e)
        {
            this.pictureBox1.Dock = System.Windows.Forms.DockStyle.None;
            this.pictureBox1.Height = 150;
            this.pictureBox1.Width = 200;
        }

LS 的是一步到位 要是逐渐变大的话更麻烦。。。。

加上定时器就可以了,以前做过窗体从透明慢慢显现的!

逐渐变大也有，只是原帖找不到不好转 ，就是这个 鼠标滚动实现图片的放大和缩小(C#2.0)

private void pictureEdit1_Properties_MouseWheel(object sender, MouseEventArgs e)
        {
            
            Rectangle oldrct;
            Bitmap bmp;
            bmp = (Bitmap)this.pictureEdit1.Image;
            oldrct = new Rectangle(0, 0, bmp.Width, bmp.Height);
            this.pictureEdit1.Image = bmp;
            Bitmap tmpbmp = null;
            int i = e.Delta;
            if (i > 0)
            {
                tmpbmp = new Bitmap(bmp.Width * 2, bmp.Height * 2);
            }
            else
            {
                tmpbmp = new Bitmap(bmp.Width / 2, bmp.Height / 2);
            }
            Graphics g = Graphics.FromImage(tmpbmp);
            Rectangle newrct = new Rectangle(0, 0, tmpbmp.Width, tmpbmp.Height);

            g.DrawImage(bmp, newrct, oldrct, GraphicsUnit.Pixel);//newrct是你的目标矩形位置，oldrct是你原始图片的起始矩形位置 
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            //oldrct = oldrct;
            pictureEdit1.Image = tmpbmp;
            g.Dispose();
            pictureEdit1.Update();
        } 

配合楼上的dd就好了