If you want the trigger to fire as soon as the contents are changed, you need to set the property value to "Property Changed".)Now for the meat of this post - the Combo Box for the Category List.
Creating a Combo Box that displays the list is quite simple.
I could use the querystring to do this but I dont think thats the way its meant to work. you can use the query string...its better you store the value in a session because storing simple string values in session is recommended than storing heavy datatables or so.....unlike querystring, session values will never be shown in url also...its secure too.
you can use the line just above msgbox statement also include your code in block : if not ispostback then end if actually wht happened is u wrote ur code directly in the pag_load n every time ur page gost postback ur dropdown got refilled n it is giving u the illusion it is not changing value of selectedindex change i m writing in C# convert in VB put all ur code in the if(! Is Post Back) block so that ur dropdown will be filled once n wil persist the data n upon change the index u wil be able to see the changing value hope this helps If I put all the code in a 'if not page.ispostback' then nothing will load the next time the page loads after autopostback, I think I am going to have to use the querystring or session variable if I can not find a simple solution.
This makes the databinding easier, since elements will walk up the element tree to find their datacontext.
If we define out Products Combo Box like this (I've eliminated the attached properties and other styling from these samples for readability):(Rember for Text Boxes, the Update Source Trigger default is Lost Focus.
Changing the Selected Item in the Combo Box should update the Category Parent property of the Product.
The way I like to set up detail forms is to have my Selector Combo Box (in this case for Products) at the top, and then the detail below in a Grid panel.
(The actual business requirement was more sensible. If the previous entity wasn’t saved, the user would be presented with a save dialog and standard “yes/no/cancel” options.
Public Class My List Object Private _mylist As New Observable Collection(Of String) Private _selected Name As String Public Sub New(By Val name List As List(Of String), By Val default Name As String) For Each name In name List _mylist. Add("Tim") obj2 = New My List Object(namelist2, "Tim") odp = Direct Cast(Me. Edit: Selected Item does work, on the proviso that the combobox contains more than one item.
Add(name) Next _selected Name = default Name End Sub Public Read Only Property My List() As Observable Collection(Of String) Get Return _mylist End Get End Property Public Read Only Property Selected Name() As String Get Return _selected Name End Get End Property End Class Class Window1 Private obj1 As My List Object Private obj2 As My List Object Private odp As Object Data Provider Public Sub New() Initialize Component() Dim namelist1 As New List(Of String) namelist1. Add("Steve") obj1 = New My List Object(namelist1, "Steve") . Find Resource("My List Object"), Object Data Provider) odp. If only one item is contained then Selected Item still does not work! I'm having a similar issue unfortunately as well with Selected Item but in my case my source is updated first before the target when my Mode is Two Way which from what I understand is backwards.
The Text Boxes were bound to the View Model’s Text Box Text property and the Combo Boxes to the Combo Box Selected Item property. By assigned a NOP (no operation) lambda, I don’t have to check whether any listeners are registered for the event.
I can simply fire the event and worse case scenario, I execute an empty function body rather than throwing a Null Reference Exception. With the INotify Propety Changed in place, changing one Text Box will cause its twin to display the same value and same for the two Combo Boxes.
, to which the combo box still appears to hold a reference at this moment – which brings it down to a question of proper coercion.