Help me to optimize my EnhancedPictureBox

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C#

Hi everyone!
I've created a new class derived from PictureBox to save heap memory
cause when using PictureBox.Image or PictureBox.ImageLocation properties
it loads the images into heap memory and the Working Set sometimes jumps
even to 120 MB (when navigating among pictures and creating new Bitmap
objects)

Instead I draw the images directly at the PictureBox.ClientRectangle surface using Graphics class

Code:

public  class EnhancedPictureBox: PictureBox
{

  public EnhancedPictureBox()
  {
     this.Image = null;
     // --- I don't use Image property ---
  }

  // --- path to an image file to draw ---
  private string path = null;

  public string PathToDraw
  {
     get { return this.path; }
     set
     { 
        this.path = value;
        if (PathToDraw != null)
           Draw(); // --- if an image exists ---
     }
  }

  private void Draw()
  {
     using(Stream stream = new FileStream(PathToDraw, FileMode.Open))
     {
        using(Image image = Image.FromStream(stream))
        {
           using( Graphics grfx = this.CreateGraphics())
           {
              grfx.DrawImage(image, 0,0, this.Width, this.Height);
           }
        }
     }
  }

  protected override void OnPaint(PaintEventArgs e)
  {
     Draw();
  }
}

Now my program eats only 30 MB!!!!!!!!

I have some questions:
First, is ot effective to use streams when loading files ....
I'm searching for the best solution so my class would not load anything to heap, but read everything from a hard drive ...
I've been searching MSDN and I found that there is
an UnmanagedMemoryStream in System.IO namespace...

How to use it to reference directly to the image on the hard drive with this stream ... It uses some IntPtr pointers... what is that?? I know it operates unmanaged code but the performance is better ...

Is there any specialized image reading streams in .NET Framework????

Please help!

[edit]Code block added to tidy up formatting. OriginalGriff[/edit]