使用矩阵C＃进行缩放以指向

Question

我想使用矩阵对点进行简单的缩放。我尝试了几种方法，例如使用zoomfactor缩放矩阵，但它只能缩放到左上角（0,0）。
如何通过鼠标将其缩放到任意给定位置？

那是我有atm的代码。

 private void DrawToBitmap()
    {
        Brush b = new SolidBrush(Color.White);
        graphics.Clear(pic.BackColor);
        graphics.SmoothingMode = SmoothingMode.HighQuality;

        float width = maxX - minX; //8000 units wide
        float height = maxY - minY;//8000 units high

        transform = new Matrix();
        transform.Scale(bmp.Width / width, bmp.Height / height);
        transform.Translate(-minX, -minY, MatrixOrder.Prepend);
        graphics.Transform = transform; 

//Works fine until now

    }


// using this method to draw the image of the bmp to the picturebox

 private void Pic_Paint(object sender, PaintEventArgs e)
    {
        DrawToBitmap();
        Graphics g = e.Graphics;
        g.DrawImage(bmp, 0, 0);
    }




 //that's what I've already gathered from the internet...it works fine 
 when i define a rectangle inside the Pic_Paint Method(just like the code 
 example shows below) and call draw 
 rectangle. It zooms in at the desired point just like i want it, but it 
 doesn't work with the DrawToBitmap method... to be totally honest I'm 
 pretty overtaxed when it comes to matrices since i've never used them



 private void Pic_Paint(object sender, PaintEventArgs e)
    {
        //Graphics g = e.Graphics;
        //g.Transform = transform;

        //Pen mypen = new Pen(Color.Red, 5);
        //Rectangle rect = new Rectangle(10, 10, 30, 30);
        //e.Graphics.DrawRectangle(mypen, rect);

    }

 protected override void OnMouseWheel(MouseEventArgs mea) //changed
    {
        pic.Focus();
        if (pic.Focused == true && mea.Delta !=0 )
        {
            Point picPoint = 
            pic.PointToClient(this.PointToScreen(mea.Location));
            ZoomScroll(picPoint, mea.Delta > 0);
        }


 private void ZoomScroll(Point location, bool zoomIn)
    {

        float newScale = Math.Min(Math.Max(zoomingfactor + (zoomIn ? 
        scrollvalue : -scrollvalue), 0.1f), 10);

        if (newScale != zoomingfactor)
        {
            float adjust = newScale / zoomingfactor;
            zoomingfactor = newScale;


            transform.Translate(-location.X, -location.Y, 
            MatrixOrder.Append);


            transform.Scale(adjust, adjust, MatrixOrder.Append);


            transform.Translate(location.X, location.Y, 
            MatrixOrder.Append);

            pic.Invalidate();
        }
    }

可能要知道的重要一点是，我使用计时器不断调用DrawBitmap（），该对象通过图形绘制对象的位置。FillEllipse（...）

如果能帮助我，将非常感谢，请随时询问更多信息！