Routing ComboBox SelectionChanged - WPF Discussion Boards

14-Jul-08 11:46

Hi All,

I feel like I should know the answer to this by now but I'm stuck.

I have a number of combo boxes in the UI, the contents of one is dynamic based on the selected item of another. All the comboboxes are bound to OberservableCollections created in a static ComboBoxManager class.

Whats the best way of handling the selection changing in the first combobox in order to populate the second combobox with the correct contents?

How do I get this selection changed event into this other class? Do I have to register a custom event in the ComboBoxManager class? Or can I create a 'Selection' property on the ComboBoxManager class and bind the first comboboxes selected item to it in a two way binding to this property and add a handler to this property to kick off some code when it changes?

Or is this all a bit overkill and I just need to use a RoutedEvent listener in the ComboBoxManager class??

Jammer

Going where everyone here has gone before! Smile | :)

Jammer15-Jul-08 2:57

15-Jul-08 2:57

Hi All,

I've just created a small expample solution showing what I'm trying to do. I want to keep all the code out of the Window1 class basically whilst pointing the comboboxes to the event hander in the ComboBoxManager class. You can get the solution here:

EventRouting.zip[^]

Any input on this would be really appricated.

Jammer

Going where everyone here has gone before! Smile | :)

Pete O'Hanlon15-Jul-08 9:23

15-Jul-08 9:23

Jammer mate. The answer to your problems is here[^].

Deja View - the feeling that you've seen this post before.

Jammer15-Jul-08 9:31

15-Jul-08 9:31

Hey Fella,

Ahhh! Josh Smith ... you know what's crazy thing ...

The application I'm working on for my employer uses Dan Crevier's DM-V-VM models extensively. We've also wrapped up the access to each data model (one per screen in the app) in a plug-in architecture where everything communicates through interfaces making it all really modular. Two developers can work on the contents of two screens without ever going near each others code/implementation. Its a really neat solution.

For my app (of which you are very aware! Wink | ;)

I started out thinking that this was a tad overkill. How wrong was I? I've only scanned this Josh Smith article so far ... methinks I need to down tools and have a rethink ...

Thanks chap.

Jammer

Going where everyone here has gone before! Smile | :)

Pete O'Hanlon15-Jul-08 9:41

15-Jul-08 9:41

If I can give any advice, it's read Josh's article on MVC and his Podder series. When you get your head round those, you finally say - "Damn it. I get it now. Now I know why I should be doing things this way in WPF." The MVC article, for me in particular, was the missing piece - the bit I needed to get it all working in my head (well, that and thinking about WPF from an ASP.NET point of view - take a look at my article on WPF if you want to see what I mean).

Deja View - the feeling that you've seen this post before.

Jammer15-Jul-08 9:43

15-Jul-08 9:43

Josh rocks ... will do fella!

Jammer

Going where everyone here has gone before! Smile | :)

Pete O'Hanlon15-Jul-08 9:49

15-Jul-08 9:49

Jammer wrote:
Josh rocks

That's why he's the RockStar.

Deja View - the feeling that you've seen this post before.

Jammer15-Jul-08 9:50

15-Jul-08 9:50

Indeed!! Now get back to your beta testing! Wink | ;)

Jammer

Going where everyone here has gone before! Smile | :)

Pete O'Hanlon15-Jul-08 9:53

15-Jul-08 9:53

Yes boss - although I might just wait for the new loose coupled, MVC SampleSort.

Deja View - the feeling that you've seen this post before.

Jammer15-Jul-08 10:00

15-Jul-08 10:00

Oooh ... imagine ... a slide out search criteria panel ...

I feel all slinky just thinking about it! It makes so much sense when I think about it ...

You know, I think what put me off it all for SS was that I started reading Dan's DM-V-VM blog when a new contractor started at work, at that time I had been looking at/using C# for all of two weeks and WPF for about 3 days (this was back in Feb) and it so confused me at the time. To be completely honest I wasn't even aware of the issues/limitations/obstacles that it was addressing let alone be in a position to really appreciate why such a pattern was at all beneficial.

After working with FoxPro for so long prior to that I was still getting my head around where my data was!!!! Wink | ;)

But, but ... where are the tables goddammnit!!!!

Oh ... fond memories ...

Jammer

Going where everyone here has gone before! Smile | :)

Pete O'Hanlon15-Jul-08 10:06

15-Jul-08 10:06

Hey - I've been coding for nigh on 30 years. Don't worry about it, there's still shedloads for me to learn in WPF. That's the beauty of it.

Deja View - the feeling that you've seen this post before.

Jammer15-Jul-08 10:12

15-Jul-08 10:12

Indeed, I do find myself getting annoyed that I should *really* get some things by now, I need to remember that I'm a real newbie to all this, I'm still encountering more new topics every day than ones I feel comfortable with ...

I spent most of today battling with dynamically generated SSIS packages ... hairy business I can tell you!

Anyway, this is really drifting OT now! Wink | ;)

Jammer

Going where everyone here has gone before! Smile | :)

How to bind Listview to Ilist

chandra vempati14-Jul-08 5:43

chandra vempati

14-Jul-08 5:43

i have a small rec in which i have to bind the listview with the Ilist which is a generic collection.

cheers
chandu

Mark Salsbery14-Jul-08 9:39

Mark Salsbery

14-Jul-08 9:39

Data Binding Overview: Binding to Collections[^]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

amistry_petlad14-Jul-08 9:41

amistry_petlad

14-Jul-08 9:41

create on class like product

and do the following things
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public class Product
{
private string _productName;

public string ProductName
{
get { return this._productName; }
set { this._productName = value; }
}

public Product()
{

}
}

--------------------
then create other calls

public class ProductRepository
{
public static IList<product> GetProducts(string criteria)
{
string key = "Products_" + criteria[0];

IList<product> list = CacheRepository.GetObjects<product>(key);

if (list == null || list.Count == 0)
{
list = DataAccess.GetProducts(criteria);
CacheRepository.SaveObject(key, list);
}

// return the list based on the criteria

List<product> productList = list as List<product>;

list = productList.FindAll(delegate(Product product)
{
return product.ProductName.ToLower().StartsWith(criteria.ToLower());
});

return list;
}
}

-------------------------------

public class DataAccess
{
public static IList<product> GetProducts(string criteria)
{
List<product> list = new List<product>();

// Fill the list with any data source

while (reader.Read())
{
Product product = new Product();
product.ProductName = reader["name1"] as String;
list.Add(product); //which fill the list
}
}

return list;
}
}

------------------------------

Then

in the Page_Load or any method
you can bind this way

IList<product> list = null;

Listview listview = new Listview();
listview.DataSource = list;
listview.DataBind();

chandra vempati14-Jul-08 10:14

chandra vempati

14-Jul-08 10:14

I am using Nhibernate.
how to get data from database , assign the result set to the Ilist and bind that Ilist to the ListView in wpf.

thanks for your reply...
its helpful

cheers
chandu