having troubles inserting a new node in a treeview

Question

I have a program that has a feature to add a node in a treeview, if the treeview item that will hold the new node has no childs a new List<TreeViewItem> with the new node is asigned to the ItemsSource property, the new node is displayed but the expand simbol (+) in the treeviewitem where the new node was added is not shown.
¿Any ideas?
Greetings.

Answer 1

List<TreeViewItem> should be of type ObservableCollection for VisualTree to listen to its change. But...

You should not add TreeViewItems to TreeView or TreeViewControls. Conceptually, these are meant to display hierarchichal data so you should add child node object to parent node object.

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Answer 2

Hi Carlos,

I can not understand why "+" symbol is not expected to be shown when it has multiple child elments, would you please clarify?


Best regards,
Bruce Zhou

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Answer 3

Imagine i have something like:

if(myTreeViewItem.ItemsSource ==null)
{
   List<TreeViewItem> myChilds = new List<TreeViewItem>();
   myChilds.Add(theNewNode;
   myTreeViewItem.ItemsSource =myChilds;
}

my screen shows the "myTreeViewItem" and "myChilds" contents but theres no "expantion + sign" in the left side of the "myTreeViewitem" tvi...

Answer 4

Hi,
Can you post the full code.

Thank You

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Answer 5

        private void MueveNodo(List<TreeViewItem> itemSelecPadre)
        {
            if (itemSelecPadre.Count > 1)
            {
                List<TreeViewItem> hijos = (List<TreeViewItem>)itemSelecPadre[1].ItemsSource;
                hijos.Remove(itemSelecPadre[0]);
                itemSelecPadre[1].Items.Refresh();
            }
            else
            {
                List<TreeViewItem> hijos = (List<TreeViewItem>)Ventana.treeView.ItemsSource;
                hijos.Remove(itemSelecPadre[0]);
                Ventana.treeView.Items.Refresh();
            }
            if (target.ItemsSource != null)
            {
                List<TreeViewItem> hijos = (List<TreeViewItem>)target.ItemsSource;
                hijos.Add(itemSelecPadre[0]);
                target.IsExpanded = true;
                target.Items.Refresh();
            }
            else
            {
                List<TreeViewItem> hijos = new List<TreeViewItem>();
                target.ItemsSource = hijos;
                hijos.Add(itemSelecPadre[0]);

                target.IsExpanded = true;
            }
            IFachadaTesauro fac = new FachadaTesauro();
            TemaTO padre = (TemaTO)target.Tag;
            TemaTO hijo = (TemaTO)itemSelecPadre[0].Tag;
            hijo.IDPadre = padre.IDTema;
            int error = fac.actualizaPadre(hijo);
            if (hijo.Materia != padre.Materia)
            {
                error = fac.actualizaMateria(hijo.IDTema, padre.Materia);
            }
            Ventana.treeView.UpdateLayout();
        }

The specific part where the trouble is is on the

if (target.ItemsSource != null)

 block.

Answer 6

Hi


Here, i am sending the example of code test it ur side. it's working my side perfectly


http://www.sendspace.com/file/g0pzws