C#控件picturebox实现图像鼠标拖拽和大小缩放

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            switch (comboBox1.SelectedIndex)
            {
                case 0: SetTypography(2, 3); break;
                case 1: SetTypography(3, 3); break;
                case 2: SetTypography(4, 3); break;
                default:
                    break;
            }
        }

        private void SetTypography(int x,int y)
        {
            panel1.Controls.Clear();
            for (int i = 0; i < y; i++)
            {
                for (int j = 0; j < x; j++)
                {
                    PictureBox pbox = new PictureBox();
                    pbox.Image = Image.FromFile(@"C:\Users\ws\Desktop\one team one goal.jpg");
                    pbox.SizeMode = PictureBoxSizeMode.Zoom;
                    pbox.Width = 250;
                    pbox.Height = 150;
                    pbox.DoubleClick += Pbox_DoubleClick;
                    pbox.Location = new Point(i * 260+10, j *150+10);
                    panel1.Controls.Add(pbox);
                }
            }
        }

        int zoomStep = 50;
        private void Pbox_MouseWheel(object sender, MouseEventArgs e)
        {
            PictureBox pbox = sender as PictureBox;
            int x = e.Location.X;
            int y = e.Location.Y;
            int ow = pbox.Width;
            int oh = pbox.Height;
            int VX, VY;  //因缩放产生的位移矢量
            if (e.Delta > 0) //放大
            {
                //第①步
                pbox.Width += zoomStep;
                pbox.Height += zoomStep;
                //第②步
                PropertyInfo pInfo = pbox.GetType().GetProperty("ImageRectangle", BindingFlags.Instance |
                 BindingFlags.NonPublic);
                Rectangle rect = (Rectangle)pInfo.GetValue(pbox, null);
                //第③步
                pbox.Width = rect.Width;
                pbox.Height = rect.Height;
            }
            if (e.Delta < 0) //缩小
            {
                //防止一直缩成负值
                if (pbox.Width < 300)
                    return;

                pbox.Width -= zoomStep;
                pbox.Height -= zoomStep;
                PropertyInfo pInfo = pbox.GetType().GetProperty("ImageRectangle", BindingFlags.Instance |
                 BindingFlags.NonPublic);
                Rectangle rect = (Rectangle)pInfo.GetValue(pbox, null);
                pbox.Width = rect.Width;
                pbox.Height = rect.Height;
            }
            //第④步，求因缩放产生的位移，进行补偿，实现锚点缩放的效果
            VX = (int)((double)x * (ow - pbox.Width) / ow);
            VY = (int)((double)y * (oh - pbox.Height) / oh);
            pbox.Location = new Point(pbox.Location.X + VX, pbox.Location.Y + VY);
        }


        Point oldPoint = default;
        private bool isMove=false;
        private Point mouseDownPoint;

        private void Pbox_DoubleClick(object sender, EventArgs e)
        {
            PictureBox pbox = sender as PictureBox;

            if (pbox.Width == 250)
            {
                oldPoint = pbox.Location;
            }
            if (pbox.Width == 250)
            {
                pbox.Width = 780;
                pbox.Height = 458;
                pbox.MouseWheel += Pbox_MouseWheel;
                pbox.MouseDown += pictureBox1_MouseDown;
                pbox.MouseUp += pictureBox1_MouseUp;
                pbox.MouseMove += pictureBox1_MouseMove;
                pbox.Location = new Point(10, 0);
                pbox.BringToFront();
            }
            else
            {
                pbox.Width = 250;
                pbox.Height = 150;
                pbox.Location = oldPoint;
                pbox.MouseWheel -= Pbox_MouseWheel;
                pbox.MouseDown -= pictureBox1_MouseDown;
                pbox.MouseUp -= pictureBox1_MouseUp;
                pbox.MouseMove -= pictureBox1_MouseMove;
            }
        }

        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            PictureBox pbox = sender as PictureBox;
            if (e.Button == MouseButtons.Left)
            {
                mouseDownPoint.X = Cursor.Position.X; //记录鼠标左键按下时位置
                mouseDownPoint.Y = Cursor.Position.Y;
                isMove = true;
                pbox.Focus(); //鼠标滚轮事件(缩放时)需要picturebox有焦点
            }
        }

        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                isMove = false;
            }
        }

        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            PictureBox pbox = sender as PictureBox;
            pbox.Focus(); //鼠标在picturebox上时才有焦点，此时可以缩放
            if (isMove)
            {
                int x, y;   //新的pictureBox1.Location(x,y)
                int moveX, moveY; //X方向，Y方向移动大小。
                moveX = Cursor.Position.X - mouseDownPoint.X;
                moveY = Cursor.Position.Y - mouseDownPoint.Y;
                x = pbox.Location.X + moveX;
                y = pbox.Location.Y + moveY;
                pbox.Location = new Point(x, y);
                mouseDownPoint.X = Cursor.Position.X;
                mouseDownPoint.Y = Cursor.Position.Y;
            }
        }

参考来自：https://www.jb51.net/article/147868.htm