CODEWITHSUNDEEP
c#wpf
Bender
Bender

Reputation: 523

Can't return the root node of TreeView

I want to get the root node of selected item in TreeView, for example, if I've:

Italy
     Serie A

and the user select Serie A, in the code was return Italy parent root. So I've create this variable inside a method:

var country = FindRootNode(nation_team.SelectedItem);

and this is the method:

private TreeViewItem FindRootNode(TreeView treeNode)
{
    while (treeNode.Parent != null)
    {
        treeNode = (TreeView)treeNode.Parent;
    }
     return treeNode;
}

but I'm not sure if this code is correct, anyway, return treeNode is underlined in red, with this error:

Can not implicitly convert type System.Windows.Controls.TreeView in System.Windows.Controls.TreeViewItem

Upvotes: 0

Views: 183

Answers (1)

Christo S. Christov
Christo S. Christov

Reputation: 2309

You are assigning treeNode which is a TreeView object to a TreeViewItem object.

With this line :

treeNode = (TreeView)treeNode.Parent;

Before using it make sure you are casting the SelectedItem to TreeViewItem like so : 

FindRootNode(nation_team.SelectedItem as TreeViewItem)

What you are looking for is this recursive approach : 

private TreeViewItem FindRootNode(TreeViewItem currentItem){

    if(currentItem == null) return null;
    var tvi = (TreeViewItem)currentItem.Parent;
    if(tvi == null){
      return currentItem;
    }
    else{
        return FindRootNode(tvi);
    }
}

Or this iterative one :

private TreeViewItem FindRootNode(TreeViewItem currentItem){
     if(currentItem == null) return null;
     while(currentItem.Parent as TreeViewItem!= null){
         currentItem = currentItem.Parent as TreeViewItem;
     }
     return currentItem;
}

Upvotes: 1

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