Question

I was using a CheckedListBox to display a List of Plugin. And i’m using an EventHandler :

private void myCheckedListBox_SelectedIndexChanged(object sender, EventArgs e)
{
    myGUIUtilities.SetDescription(myCheckedListBox.SelectedItem, myRichTextBox);
}

To display something …
This is the myGUIUtilities.SetDescription method :

internal static void SetDescription(object p_SelectedObject, RichTextBox p_TextBoxDescription)
            {
                AbstractEnvChecker l_Plugin = p_SelectedObject as AbstractEnvChecker;
                if (l_Plugin != null)
                    p_TextBoxDescription.Text = l_Plugin.Description;
            }

To display my Plugins I just used the CheckedListBox.Items.Add method :

MyCheckedListBox.Items.Add(myPlugin);

That accepts an object as argument …

Now i want to classify my Plugins by cetgories, so i’m using TreeView and TreeNode.

The problem is that the TreeView.Nodes.Add(TreeNode node) accepts only TreeNode Type as argument.

And i can’t actually use the same SetDescription method which needs a Plugin Type to get the Plugin.Description Property …

Is there a way to pass an object to the TreeView.Nodes.Add(TreeNode node) method ?
Or another way to do that ?

Answer 1

Use the Tag property on the tree node to attach an object to it. Then you can pull it back out again later.

So you could do this (assuming a Name property on the plugin object)

public TreeNode AddPluginNode(TreeNode parent, AbstractEnvChecker plugin)
{
  TreeNode created = new TreeNode(plugin.Name) { Tag = plugin };
  parent.Nodes.Add(created);
  return created;
}

And then you can rewrite the start of your event handler thus:

AbstractEnvChecker l_Plugin = p_SelectedObject as AbstractEnvChecker;
if(l_Plugin == null)
{
  TreeNode selNode = p_SelectedObject as TreeNode;
  if(selNode != null && selNode.Tag != null)
    l_Plugin = selNode.Tag as AbstractEnvChecker;
}
//might still be null in the future if you start using Tags for other types.