Are there weak links in .NET?

Question

I would like to keep a list of a specific class of objects in my application. But I still want the object to be garbage collected. Can you create weak links in .NET?

For reference:

• Trash Collection of objects that track their own instances in an internal map.
• Create a weak link to the object

Reply From MSDN:

To establish a weak link using an object, you create a WeakReference using an instance of the object to be tracked. Then you set the target property for this object and set object to null. For sample code, see WeakReference in the class library.

Answer 1

Yes, there is a common weak reference class.

MSDN> Weak Link

Answer 2

Can you create weak links in .NET?

Yes:

WeakReference r = new WeakReference(obj); 

Uses System.WeakReference .

Answer 3

Yes...

There is a pretty good example that can be found here:

http://web.archive.org/web/20080212232542/http://www.robherbst.com/blog/2006/08/21/c-weakreference-example/

Answer 4

Here is a complete implementation example (insecure) of WeakReference implementation

 ClassA objA = new ClassA(); WeakReference wr = new WeakReference(objA); // do stuff GC.Collect(); ClassA objA2; if (wr.IsAlive) objA2 = wr.Target as ClassA; else objA2 = new ClassA(); // create it directly if required 

WeakReference is located in the System namespace, so there is no need to include any special assembly in it.