Winforms TreeView Serialization which includes Node Tag-attribute objects

Winforms TreeView Serialization which includes Node Tag-attribute objects

How can I (binary) serialize a "WinForm Treeview" into a file, so that
also objects, which are assigned to the "Node-Tag-Attribute" are also
saved. I need serialization and deserialization (into the treeview again).
I have tried the following solution: Saving content of a treeview to a
file and load it later, but after deserialization all tag attributes,
which consists of objects original treeview, are now = null.