Question

I have a class “skImage”. This class has a private variable (with a public property that exposes it)

private Image _capturedImage;  

the constructor of this class looks like:

   public skImage(Image captured) {

            _capturedImage = captured;

        }

It also has the following method:

public bool Invert() {

        Bitmap b = new Bitmap(_capturedImage);

        unsafe {
         //random code not relevant.
        }

        _capturedImage = b;
        b.Dispose();
        return true;
    }

and then it has a save() method, which just calls:

  _capturedImage.Save(_saveFullLocation);

now if i run the invert method and then try calling save it throws an exception (parameter is not valid). After googling this exception it seems like I am disposing of the image. I can see that I am disposing “b” after the invert method.

My question is that when i do _capturedImage = b does that mean both variables now hold one reference to the object? I dont want that. I want b to be destroyed to relieve memory so the GC can collect it. How do i transfer b to _capturedImage and destroy b.

thanks

Answer 1

does that mean both variables now hold one reference to the object?

Yes. However, a reference is only a reference – it does not cost much memory.

I want b to be destroyed

You cannot destroy a reference – you can only dispose the object itself.

Instead of disposing b you should write:

_capturedImage.Dispose();
_capturedImage = b;