'StackOverflowException was unhandled' errors in C#

Question

I have a problem with my code. I finally got it so there were no errors, but now i have to deal with stackoverflow...

can someone tell me what is wrong with my code?

    public Matrix Projection
    {
        get { return Projection; }
        protected set 
        {
            Projection = value;
            generateFrustum();
        }
    }

It would be nice if you could help!

thanks

Answer 1

Your set method calls itself: Projection = value.

private Matrix _projection = null;
public Matrix Projection
{
    get { return _projection; }
    protected set 
    {
        _projection = value;
        generateFrustum();
    }
}

When you use following form:

public Matrix Projection { get; set }

you don't need to specify variable to store actual value, but when you implement get or set explicitly you should declare additional variable and use it in get, set implementations.

Answer 2

You are defining an infinite recursion on your get and set functions.

get { return Projection; }

is equivalent to:

get { return get();}.

Answer 3

public T PropA { get; set; } 

is actually syntax of

T _PropA; public T PropA { get { return _PropA; } set { _PropA = value; } }

So the answer will be

private Matrix _projection = null;
public Matrix Projection
{
    get { return _projection; }
    protected set 
    {
      _projection = value;
      generateFrustum();
    }
}

you can see read below examples for more info
http://msdn.microsoft.com/en-us/library/ms228503.aspx
http://msdn.microsoft.com/en-us/library/w86s7x04(v=vs.80).aspx

Answer 4

Properties' setters and getters are implemented as methods (get_X and set_X).

Writing Projection = value within the Projection's setter, causes a recursive call to set_Projection() from within set_Projection(). (The same applies to get_Projection().)

Since there is no condition surrounding the call, the recursion is infinite.

As for public T PropA { get; set; }, it is sugar syntax for:

private T _PropA;

public T PropA
{
    get
    {
        return _PropA;
    }
    set
    {
        _PropA = value;
    }
}

What you should do is:

private Matrix _projection;

public Matrix Projection
{
    get
    {
        return _projection;
    }
    protected set 
    {
        // Make sure that Matrix is a structure and not a class
        // override == and != operators in Matrix (and Equals and GetHashCode)
        // If Matrix has to be a class, use !_project.Equals(value) instead

        // Consider using an inaccurate compare here instead of == or Equals
        // so that calculation inaccuracies won't require recalculation

        if (_projection != value)
        {
            _projection = value;
            generateFrustum();
        }
    }
}