SilverlightShow: Make the TreeView control to be MVVM compliant Comments

Re: Make the TreeView control to be MVVM compliant

rookie07 — Mon, 19 Dec 2011 17:20:33 GMT

ok, i think i figured it out. i coded a simple helper class derived from INotifyPropertyChanged and bound it to the TextBox - may be i've got something wrong, but i thought the notification behaviour would be automatically be added because ViewModel is indirectly derived from it???

    public class HierarchicalViewModelNotifier : INotifyPropertyChanged
    {
        private HierarchicalViewModel _currentViewModel = null;
        public HierarchicalViewModel CurrentViewModel { get { return _currentViewModel; } set { _currentViewModel = value; Changed("CurrentViewModel"); } }
        public event PropertyChangedEventHandler PropertyChanged;
        private void Changed(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

public class MainPageViewModel : ViewModel
{

public HierarchicalViewModelNotifier ViewModelNotifier { get; set; }

...

public MainPageViewModel()
        {
            ViewModelNotifier = new HierarchicalViewModelNotifier();
            ViewModelNotifier.CurrentViewModel = Root.FirstOrDefault();

...

}

private void ClickItem(HierarchicalViewModel item)
        {
            ViewModelNotifier.CurrentViewModel = item;
        }

and in the XAML i did it like this way:

so let's look where i might stuck next ;o)

Re: Make the TreeView control to be MVVM compliant

rookie07 — Mon, 19 Dec 2011 16:46:16 GMT

very nice article!

i'm getting slowly into the mvvm thing...so there is still a problem which i have to solve. supose i want to bind a TextBox.Text to the ItemClickedCommad how to get this done?

i added a propety to the MainPageViewModel like:

public HierarchicalViewModel CurrentViewModel { get; set; }

in order to connect the data to the event:

private void ClickItem(HierarchicalViewModel item)
        {
            CurrentViewModel = item;
        }

in the XAML i thought i could do something like:

but it seems that the textbox is never updated...? what am i doing wrong?

thanx!

Re: Make the TreeView control to be MVVM compliant

rookie07 — Mon, 19 Dec 2011 16:00:46 GMT

very nice article!

i'm getting slowly into the mvvm thing...so there is still a problem which i have to solve. supose i want to bind a TextBox.Text to the ItemClickedCommad how to get this done?

i added a propety to the MainPageViewModel like:

public HierarchicalViewModel CurrentViewModel { get; set; }

in order to connect the data to the event:

private void ClickItem(HierarchicalViewModel item)
        {
            CurrentViewModel = item;
        }

in the XAML i thought i could do something like:

but it seems that the textbox is never updated...? what am i doing wrong?

thanx!

RE: Make the TreeView control to be MVVM compliant

Bill Gan — Wed, 25 May 2011 08:08:10 GMT

nice article!

RE: Make the TreeView control to be MVVM compliant

Andrea Boschin — Wed, 03 Nov 2010 10:03:27 GMT

thanks marcos, unfortunately there is not any "official manual" of MVVM since it is a young matter. You have to follow blogs and twits and try it by yourself, and perhaps contributing to the pattern yourself :)

RE: Make the TreeView control to be MVVM compliant

marcos — Wed, 03 Nov 2010 02:53:53 GMT

Hi Andrea !

I would like to give you congratulations for such a nice article !. I plugged your generic solution into a Silverlight Navigation application so now my app users will be able to navigate to the application's pages through the TreeView navigation system.

Your generic implementation and clean code are amazing ! I'm actually getting used to the MVVM pattern (I come from the Java Swing MVC) could you give me a clue from where I can learn more about MVVM ?

Thank you very much !
--marcos

RE: Make the TreeView control to be MVVM compliant

jsp3536 — Tue, 05 Jan 2010 19:51:25 GMT

That is a nice solution. One thing to think about is if your application uses theming then now the tree control will not be themed since it has been derived from a the base tree control. If you still require theming you can just wire up the events on the treecontrol like normal and then in the events call the commands that are on the view model.