Pass generic parameter for Treeview & TreeNode

Question

I have the following two methods which loop either a TreeView or TreeNode which I want to combine into a single method. Instead of passing the TreeView/TreeNode I could pass an Object and check the type but wanted to know if there was better way?

private TreeNode SearchNode(string nodetext, TreeNode node)
{
    foreach (TreeNode nd in node.Nodes)
    {
        if (nd.Text == nodetext)
        {
            return nd;
        }
    }
    return null;
}

private TreeNode SearchParentNode(string nodetext, TreeView trv)
{
    foreach (TreeNode node in trv.Nodes)
    {
        if (node.Text == nodetext)
        {
            return node;
        }
    }
    return null;
}

Answer 1

You want a single method that can search for a value in a NodesCollection, so just extract the contents of both methods into a single, third method that accepts a NodesCollection:

private TreeNode SearchNodes(string nodeText, TreeNodesCollection nodes)
{
    foreach (TreeNode node in nodes)
    {
        if (node.Text == nodeText)
        {
            return node;
        }
    }
    return null;
}

And pass it whatever collection you want to search:

return SearchNodes(nodetext, node.Nodes);

return SearchNodes(nodetext, trv.Nodes);

Also, you can reduce the SearchNodes method to a single line using LINQ:

private TreeNode SearchNodes(string nodeText, TreeNodesCollection nodes)
{
    return nodes.Cast<TreeNode>().FirstOrDefault(n => n.Text == nodeText);
}