StrataFrame Forum » StrataFrame Application Framework - V1 » Business Objects and Data Access (How do I?) » How to get changes to a property on a control to update BO when using IBusinessBindable

How to get changes to a property on a control to update BO when using IBusinessBindable

Greg McGuffey — Wed, 23 May 2007 16:27:56 GMT

I'm still not understanding how to get SF to update data if I add the IBusinessBindable interface to a control. My initial understanding was that I needed an event that changed after the bound property changed. I.e. if my control had a property called MyProperty that I wanted to be bindable (i.e. the property would be loaded with data by the BO and changes to the property would update the BO), I'd need a MyPropertyChanged event:
[codesnippet]
' The property that can be bound via SF
Private _myProperty As Integer
Public Property MyProperty() As Integer
Get
Return _myProperty
End Get
Set(value As Integer)
_myProperty = value
Me.OnMyPropertyChanged()
End Set
End Property

' The event that occurs after the property is changed
Public Event MyPropertyChanged As EventHandler
Protected Overridable Sub OnMyPropertyChanged(e As EventArgs)
Raiseevent MyPropertyChanged(Me,e)
End Sub[/codesnippet]

However, this didn't work. :(

Next I noticed that in the SF RichTextbox, you implemented the INotifyPropertyChanged interface, so I tried that. I created an event called PropertyChanged and raise that event in the set of any properties I want to be bindable. Again it didn't update the BO.

How do I get the BO to know when the property changes, so it updates itself with the new data?

RE: How to get changes to a property on a control to update BO when using IBusinessBindable

Greg McGuffey — Wed, 23 May 2007 16:27:56 GMT

Yep, its all clear now. :D And its working :w00t:

RE: How to get changes to a property on a control to update BO when using IBusinessBindable

StrataFrame Team — Wed, 23 May 2007 14:13:13 GMT

Hehe, yes, you'll have to bubble the event up for it to work. However, you only need to create the event if you're creating a custom property. For instance, we inherited TextBox and since it already had a TextChanged event, we didn't have to create a new one since we didn't define the Text property.

So, only when you define the property do you need to handle the changed events yourself. Hope that helps.

RE: How to get changes to a property on a control to update BO when using IBusinessBindable

Greg McGuffey — Tue, 22 May 2007 19:24:27 GMT

I found the problem I was having. The control was never firing either the [property]Changed event or the PropertyChanged event because I wasn't bubbling the required event up from the base control. Now [b]BOTH[/b] of the methods outlined in the original post work. :blush:

Hope this helps somebody else!