RadGrid Binding to a List - list

Question

XAML RadGrid
<telerik:RadGridView d:DataContext="{d:DesignInstance {x:Type local:A}}" Name="myGridView" Grid.Column="2" ItemsSource="{Binding Path=MyList}" Margin="7,7,7,2" IsFilteringAllowed="False" ShowColumnHeaders="True" AutoGenerateColumns="True" />
C# Code
Class A:INotifyPropertyChanged
{
private List<Fields> MyList;
public event PropertyChangedEventHandler PropertyChanged;
public List<Fields> _theList
{
get
{
if (MyList == null)
{
MyList = new List<Fields>();
}
return MyList;
}
set
{
if (MyList != value)
{
MyList = value;
PropertyChanged(this, new PropertyChangedEventArgs("_theList"));
}
}
}
}
When the items in MyList change dynamically, the radgridview does not update automatically, It works if I reset the Itemssource in the code:
mygridview.Itemssource = Null;
mygridview.Itemssource = MyList;
I have to reset the itemssource everytime in the code after the MyList changes. Why GridView does not update automatically when contents of MyList change?
Also, During design time it shows me appropriate column headers with no data in the columns because the list is empty. But when I run the application, column headers disappear and no data is displayed in the radgrid when contents of MyList change dynamically.

Answer 1

When the items in MyList change dynamically,
You're notifying when your list property changes...which doesn't cover the above scenario. In order to support what you want, I think you need a collection that supports the INotifyCollectionChanged interface.
http://msdn.microsoft.com/en-us/library/system.collections.specialized.inotifycollectionchanged.aspx
Out of the box, ObservableCollection supports this. It derives from IList<T>. So perhaps you could do:
private IList<Fields> MyList;
private IList<Fields> MyObservableList;
public event PropertyChangedEventHandler PropertyChanged;
public IList<Fields> _theList
{
get
{
if (MyObservableList == null)
{
MyObservableList = new ObservableCollection<Fields>();
}
return MyObservableList;
}
set
{
if (MyList != value)
{
MyList = value;
MyObservableList = new ObservableCollection<Fields>(MyList );
// this will throw a null reference exception if no one' is listening. You
PropertyChanged(this, new PropertyChangedEventArgs("_theList"));
}
}
}
If you can forgoe having a List<T> instance for having an ObserableCollection<T> instance, the above could be even simpler:
private ObservableCollection<Fields> MyList;
public event PropertyChangedEventHandler PropertyChanged;
public ObservableCollection<Fields> _theList
{
get
{
if (MyList== null)
{
MyList= new ObservableCollection<Fields>();
}
return MyList;
}
set
{
if (MyList != value)
{
MyList = value;
// this will throw a null reference exception if no one' is listening. You should make a method OnPropertyChanged that checks if PropertyChanged != null.
PropertyChanged(this, new PropertyChangedEventArgs("_theList"));
}
}
}
Also, as an aside, usually the private members are _camelCase and the public members are PascalCase...not sure if it's intentional.