Getting MVVM ViewModel to bind to the View - mvvm

Question

I have the following code (changed object names, so syntax/spelling errors ignore).
public class ViewModel
{
ViewModelSource m_vSource;
public ViewModel(IViewModelSource source)
{
m_vSource= source;
m_vSource.ItemArrived += new Action<Item>(m_vSource_ItemArrived);
}
void m_vSource_ItemArrived(Item obj)
{
Title = obj.Title;
Subitems = obj.items;
Description = obj.Description;
}
public void GetFeed(string serviceUrl)
{
m_vFeedSource.GetFeed(serviceUrl);
}
public string Title { get; set; }
public IEnumerable<Subitems> Subitems { get; set; }
public string Description { get; set; }
}
Here is the code I have in my page's codebehind.
ViewModel m_vViewModel;
public MainPage()
{
InitializeComponent();
m_vViewModel = new ViewModel(new ViewModelSource());
this.Loaded += new RoutedEventHandler(MainPage_Loaded);
this.DataContext = m_vViewModel;
}
void MainPage_Loaded(object sender, RoutedEventArgs e)
{
m_vViewModel.GetItems("http://www.myserviceurl.com");
}
Finally, here is a sample of what my xaml looks like.
<!--TitleGrid is the name of the application and page title-->
<Grid x:Name="TitleGrid" Grid.Row="0">
<TextBlock Text="My Super Title" x:Name="textBlockPageTitle" Style="{StaticResource PhoneTextPageTitle1Style}"/>
<TextBlock Text="{Binding Path=Title}" x:Name="textBlockListTitle" Style="{StaticResource PhoneTextPageTitle2Style}"/>
</Grid>
Is there anything I'm doing wrong here?

Answer 1

I think your ViewModel should implement the INotifyPropertyChanged interface:
public virtual event PropertyChangedEventHandler PropertyChanged;
protected virtual void RaisePropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
Then your property would look like that:
private title;
public string Title
{
get
{
return this.title;
}
set
{
if (this.title!= value)
{
this.title= value;
this.RaisePropertyChanged("Title");
}
}
}
Michael

Answer 2

Well, go figure, 10 mins after I post it, I figure it out.
I was missing the INotifyProperty implementation. Thanks if anyone is looking at this.