Question

I am attempting to learn to create graphs using Telerik.

At the moment I am working from the example available here :

http://demos.telerik.com/silverlight/#Chart/SimpleFiltering

The example ViewModel has a call to the following method :

this.OnPropertyChanged("SeriesEU27Visibility");

Am I missing an assembely/reference or is this something the user should implement ?

If the user should implement it, what would be an appropriate method in this case ?

Would this be a working solution ? :

 protected void OnPropertyChanged(string name)
      {
          PropertyChangedEventHandler handler = PropertyChanged;
          if (handler != null)
          {
              handler(this, new PropertyChangedEventArgs(name));
          }
      }

Answer 1

OnPropertyChanged changed helper methods, like the one you show, are very common and are often implemented in reusable base classes.

To use it directly in a class, that does not already inherit these features, you need to inherit INotifyPropertyChanged and declare the PropertyChanged event:

public MyClass : INotifyPropertyChanged
{
   public event PropertyChangedEventHandler PropertyChanged;
   ...
}

Note: Your initial assignment to a local variable does not speed things up, the standard code looks like:

  protected void OnPropertyChanged(string name)
  {
      if (PropertyChanged != null)
      {
          PropertyChanged(this, new PropertyChangedEventArgs(name));
      }
  }

Otherwise, yes you are spot on.