Question

I need to write a tree search method which takes a type parameter T and returns all items of type T that exist in the tree. Is there any way to do this? I would prefer elegance over efficiency at this point…

Answer 1

Something like this:

internal static IEnumerable<T> AllDescendantNodes<T>( this TreeNode input )      where T class; {     T current = null;     foreach ( TreeNode node in input.Nodes )         if( (current = node as T) != null )         {             yield return current;             foreach ( var subnode in node.AllDescendantNodes<T>() )                 yield return subnode;         } } 

You would then call this against the root node as an extension method:

foreach( MyCustomNodeClass item in rootNode.AllDescendantNodes<MyCustomNodeClass>() )  {     ... }