Binding to a dictionary in Silverlight with INotifyPropertyChanged
- by rip
In silverlight, I can not get INotifyPropertyChanged to work like I want it to when binding to a dictionary. In the example below, the page binds to the dictionary okay but when I change the content of one of the textboxes the CustomProperties property setter is not called. The CustomProperties property setter is only called when CustomProperties is set and not when the values within it are set. I am trying to do some validation on the dictionary values and so am looking to run some code when each value within the dictionary is changed. Is there anything I can do here?
C#
public partial class MainPage : UserControl
{
public MainPage()
{
InitializeComponent();
MyEntity ent = new MyEntity();
ent.CustomProperties.Add("Title", "Mr");
ent.CustomProperties.Add("FirstName", "John");
ent.CustomProperties.Add("Name", "Smith");
this.DataContext = ent;
}
}
public class MyEntity : INotifyPropertyChanged
{
public event PropertyChangedEventHandler System.ComponentModel.INotifyPropertyChanged.PropertyChanged;
public delegate void PropertyChangedEventHandler(object sender, System.ComponentModel.PropertyChangedEventArgs e);
private Dictionary<string, object> _customProps;
public Dictionary<string, object> CustomProperties {
get {
if (_customProps == null) {
_customProps = new Dictionary<string, object>();
}
return _customProps;
}
set {
_customProps = value;
if (PropertyChanged != null) {
PropertyChanged(this, new PropertyChangedEventArgs("CustomProperties"));
}
}
}
}
VB
Partial Public Class MainPage
Inherits UserControl
Public Sub New()
InitializeComponent()
Dim ent As New MyEntity
ent.CustomProperties.Add("Title", "Mr")
ent.CustomProperties.Add("FirstName", "John")
ent.CustomProperties.Add("Name", "Smith")
Me.DataContext = ent
End Sub
End Class
Public Class MyEntity
Implements INotifyPropertyChanged
Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
Private _customProps As Dictionary(Of String, Object)
Public Property CustomProperties As Dictionary(Of String, Object)
Get
If _customProps Is Nothing Then
_customProps = New Dictionary(Of String, Object)
End If
Return _customProps
End Get
Set(ByVal value As Dictionary(Of String, Object))
_customProps = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("CustomProperties"))
End Set
End Property
End Class
Xaml
<TextBox Height="23" Name="TextBox1" Text="{Binding Path=CustomProperties[Title], Mode=TwoWay}" />
<TextBox Height="23" Name="TextBox2" Text="{Binding Path=CustomProperties[FirstName], Mode=TwoWay}" />
<TextBox Height="23" Name="TextBox3" Text="{Binding Path=CustomProperties[Name], Mode=TwoWay}" />
