Question

I use TreeView in my C# project (Windows Forms) and I have a problem (obviously :P). I fill my TreeView like this:

void RefreshTreeView()
{
    treeView1.Nodes.Clear();
    for (int i = 0 ; i < categories.Count ; ++i)
    {
        treeView1.Nodes.Add(categories[i].name);
        for (int j = 0 ; j < categories[i].questions.Count ; ++j)
        {
            treeView1.Nodes[i].Nodes.Add("Pytanie nr " + categories[i].questions[j].number.ToString()
                + " za " + categories[i].questions[j].points.ToString() + " pkt. ["
                + (categories[i].questions[j].used ? "Przeczytane" : "Nieprzeczytane") + "]");
            treeView1.Nodes[i].Tag = categories[i].questions[j];   // A
        }
    }
}

In line marked “A” above I attach a Question object to Node’s Tag. And it seems to work as later on in the program I can retrieve my Question object like this:

((Question)treeView1.Nodes[0].Tag).number

But I want to get the currently selected Node’s Tag. Which I try to do like this:
((Question)treeView1.SelectedNode.Tag).number
But it doesn’t work (Tag is null). What am I doing wrong? And how to get the currently selected Node’s Tag?

Answer 1

treeView1.Nodes[i].Tag is the tag of the parent node.

You probably want to set the tag of the child node, which is treeView1.Nodes[i].Node[j].Tag