Re: 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

amistry_petlad14-Jul-08 11:34

amistry_petlad

14-Jul-08 11:34

why you can not bind the data directly to the listview rather then putting it into IList is there any specific reason?
let me know so I can help you better.
Wink | ;)

Will this may be helpful?
http://www.theserverside.net/tt/articles/showarticle.tss?id=NHibernate[^]

Good wpf tutorials

csciwizard12-Jul-08 9:42

csciwizard

12-Jul-08 9:42

I've looked at many of Sacha Barber's articles on WPF, and Josh Smith's, too. Those are great, but I am a total beginner at WPF and those articles are a bit overhead, anyone know of any total beginner tutorials on WPF?

Thanks

Pete O'Hanlon12-Jul-08 10:09

12-Jul-08 10:09

They have created some beginner tutorials as well. You may need to hunt around a bit to find them but they are there. I would also recommend reading this[^] book.

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

csciwizard12-Jul-08 12:21

csciwizard

12-Jul-08 12:21

Hi Pete,

Thanks for the amazon link. The book looks like it could be worth the money and go along with Josh and Sacha's works.

Jeff

Paul Conrad12-Jul-08 12:32

Paul Conrad

12-Jul-08 12:32

Go to the article search, if you haven't already done so, and check off WPF under technology and Skill level as Beginner, and many good stuff pop up. It may take sometime to digest it all, but I am sure you'll find it helpful along with the book Pete suggested. I've seen the book at Barnes and Noble and it is a very good looking book. The price on Amazon is good, too.

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon