Recursive method help

[Techno]

I am trying to go through each and every single treenode in a treeview.

I want to be able to return a treenode, or null, if a specific object has been found. how can I do this? I feel like i've lost all my knowledge!


private TreeNode GetObjectFromTreeView(TreeNode startingNode, MyObject objectToMatch)
{
foreach(TreeNode currentNode in startingNode.Nodes)
{
if (currentNode.Tag != null && currentNode.Tag.GetType() == typeof(MyObject))
{
return currentNode;
}

return this.GetObjectFromTreeView(currentNode, objectToMatch);

}


return null;
}

[wossname]

You're checking the type of the object (which is sensible), but not its value. If you have more than one tag of the same type then you'll simply stop at the first one, by the look of it.

[penagate]

Easier than using GetType:

currentNode.Tag is MyObject

[penagate]

Actually, you don't need to check its type: just compare references.

if (currentNode.Tag != null && Object.ReferenceEquals(currentNode.Tag, objectToMatch))

[jmcilhinney]

private TreeNode GetObjectFromTreeView(TreeNode startingNode, MyObject objectToMatch)
{
    TreeNode result = null;
 
    foreach (TreeNode currentNode in startingNode.Nodes)
    {
        if (currentNode.Tag == objectToMatch)
        {
            result = currentNode;
            break;
        }
 
        result = this.GetObjectFromTreeView(currentNode, objectToMatch);
 
        if (result != null)
        {
            break;
        }
    }
 
    return result;
}

That code will not work for value types but it will for reference types.