[Solved] SelectionMode property not responding

[Miguel Rios]

Hi to all,

I'll go directly to the problem... I am creating a treeView in the go from a flat list, i create one RadTreeVieIitem and if the item have child i add them to it with another function, and at the time if these child have child i add them to the previous items...

Now, the problem comes when i set the following properties as follow: IsOptionElementsEnabled = true, ItemsOptionListType = OptionListType.OptionList, SelectionMode = Telerik.Windows.Controls.SelectionMode.Single.

I would expect that only 1 RadTreeViewElement could be selected in the whole tree but that doesn't happen, in stead, the property SelectionMode = single only works for the child of each RadTreeViewItem, for example:

-Item1

-Item2

-Item4*

-Item5

-Item3

-Item6

-Item7*

here, only item4 or item5 can be selected at a time, but also item6 or item7, the asterics mean that they are selected I dont know if this is clear, i send a snipet of how i create the tree and the nodes

        public void createTree(RadTreeView rvTree, ObservableCollection<businessObject> obs)
        {
            try
            {
                rvTree.Items.Clear();
                rvTree.SelectionMode = Telerik.Windows.Controls.SelectionMode.Single;
                rvTree.IsOptionElementsEnabled = true;
                rvTree.ItemsOptionListType = OptionListType.OptionList;


                foreach (var a in obs)
                {
                    RadTreeViewItem tn = new RadTreeViewItem();



                    tn.Header = a.Name;  //A property of my business object


                    if (a.IsSelected == true)  //Also a property of my business object
                    {
                        tn.CheckState = System.Windows.Automation.ToggleState.On;
                        tn.IsSelected = true;

                    }

                    tn.Tag = a;

                    if (a.Nodo_Padre == 0) //Proerty of my business object that indicates the key of the father item
                    {
                        rvTree.Items.Add(tn);
                        addNodes(tn, this.obsUnAuditable);
                    }

                }
            }
            catch (Exception ex)
            {

            }
        }


        public void addNodes(RadTreeViewItem rvItem, ObservableCollection<businessObject> obs)
        {
            try
            {
                    var x = (businesobject)rvItem.Tag; //I saved my Business object in the tag of the RadTreeViewItem

                    foreach (var y in obs)
                    {
                        if (y.Nodo_Padre == x.Clave)//Property that have the fathers key
                        {
                            RadTreeViewItem item = new RadTreeViewItem();

                            item.Header = y.Nombre; //property of my businessobject

                            if (y.IsSelected == true) //Property of my business object
                            {
                                item.CheckState = System.Windows.Automation.ToggleState.On;
                                item.IsSelected = true;
                                item.Tag = y;
                                rvItem.Items.Add(item);
                                addNodes(item, this.obsUnAuditable);
                            }
                            else
                            {
                                item.Tag = y;
                                rvItem.Items.Add(item);
                                addNodes(item, this.obsUnAuditable);
                            }
                        }
                    }
            }
            catch (Exception ex)
            {

            }
        }

the tree that i give the function createTree as a parameter is created in the .xaml file.

Hope yo can help me with this, its a crucial need in the development.

Thank you!

[Kiril Stanoev]

Hi Miguel,

Unfortunately I was not able to reproduce this issue. I've attached my test project. Could you please have a look at it and let me know if I am doing anything wrong. I'd be glad to further assist you.

Greetings,
Kiril Stanoev
the Telerik team

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[Miguel Rios]

You did it good, what i meant is that i want only one item to be selected in the whole tree, in stead one item selected in each item... look, what i want is this:

-item1

-item2

-item5

-item6*(just this one selected in the whole tree)

-item3

-item7

-item8

and what the tree actually does is this:

-item1

-item2

-item5

-item6*(this is selected)

-item3

-item7*(but also this one is)

-item8

I tried to be as clear as possible, hope you got me, any doubt i'll try to exaplain it clearer.

Thank you!

[Tina Stancheva]

Hi Miguel Rios,

Please accept my apology for the delayed response.

I am not sure that I understood your scenario correctly. Do you want to allow the users to check only one item in the tree at once?

If this is what you need, then the SelectionMode property won't help you since it controls the number of selected items in your tree. When the property is set to Single, then only one item in the tree can have IsSelected=True at a time.

However, if you want to allow only one item to be checked at a time in the whole tree, you can modify the PreviewChecked()event handler to uncheck any previously checked items, like this:
while (treeView1.CheckedItems.Count > 0)
            {
                foreach (var o in treeView1.CheckedItems)
                {
                    RadTreeViewItem item = o as RadTreeViewItem;
                    if (item != null)
                    {
                        item.CheckState = System.Windows.Automation.ToggleState.Off;
                        break;
                    }
                }
            }

I attached the modified example. Can you please take a look at it and let me know if this is what you need?

Sincerely yours,
Tina Stancheva
the Telerik team

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