Question

I want to derive a class from Microsoft.Kinect.JointCollection class.

public class Derived : JointCollection 
{
    public string NewItem;

    public Derived ()
    {

    }
}

Error:

The type 'Microsoft.Kinect.JointCollection' has no constructors defined.

What is the problem and how can I solve it?

Answer 1

Base class objects are always constructed before any deriving class.
Thus the constructor for the base class is executed before the
constructor of the derived class.

http://msdn.microsoft.com/en-us/library/ms228387%28v=VS.80%29.aspx

The Microsoft.Kinect.JointCollection class does not contain a public constructor [2] so whenever you attempt to instantiante Derived it fails because a public constructor is not available on the base class.

You could consider wrapping the JointCollection class with your derived class and providing the appropriate methods to access it in Derived that do little more than call methods on JointCollection directly.