How to find out the level in the hierarchy of the selected item in TreeView?

Question

WPF

For example, there is a tree list:

- Уровень 1
   - Уровень 2
   - Уровень 2
      - Уровень 3
- Уровень 1
   - Уровень 2
      - Уровень 3
      - Уровень 3
   - Уровень 2
- Уровень 1
   - Уровень 2

It doesn't matter what the data is, but how do I get the hierarchy level of the currently selected item in the tree list?

Answer 1

When you are programming in WPF, the visual part is meant to be a reflection of your presentation of the data. Therefore, the hierarchy level of the selected item should not be found among the TreeViewItem elements, but among the parents of the selected item in accordance with the data presentation model.
Example:

class A
{
 public string Name{get;set;}
 public A Parent {get;set;}
 public IEnumerable<A> Children
 {
  get
  {
    return AllItemsOfA.Select(a => a.Parent == this);
  }
 }
 public int Level()
 {
  int level = 0;
  var current = Parent;
  while(current != null)
  {
    current = current.Parent;
    level ++;
  }
  return level;
 }
}

By adding a collection of such elements to the TreeView, you will get the hierarchy level you need for the selected element.