Hi guys
I have a big problem with the TypeDescriptionProvider?
Actully I do not know exactly for what we need this?

I have task add the implementation of the TypeDescriptionProvider to the specific class NotificationExtension
and do this like this

Apply [TypeDescriptionProvider(typeof(ZControlTypeDescriptionProvider))] attribute to control’s class
Implement method which returns metadata using the following template:

#region Metadata

public static PropertyDescriptor[] GetPropertyDescriptors()
{
return new GenericPropertyDescriptorBuilder<ControlType>()
.Property("PropertyName", "DefaultValue", registerEvent, “EventName�
.Result;
}

#endregion


I did this as follows
public static PropertyDescriptor[] GetPropertyDescriptors()
{
return new GenericPropertyDescriptorBuilder<NotificationExtension>()
.Property<INotificationPresenter>("Presenter", null, false)
.Property("Notifications", ZNotifications.Empty, false)
.Property("Notifications1", ZNotifications.Empty, false)
.Property("Notifications2", ZNotifications.Empty, false)
.Result;
}

where add to the GetPropertyDescriptors() method all the public properrties that available in that class

and of course (as I do not know what I did) I have an exception as follows

Exception Type: System.NullReferenceException
Message: Objectreferencenotsettoaninstanceofanobject.
Source: System.Windows.Forms Error binding Control : TextBox, BindTo = Z0_Description
StackTrace: at System.Windows.Forms.Binding.CheckBinding()

Please help me!
Will be glad with any ideas!

Thanks