Question

I have a wpf application using Caliburn.Micro. I need to bind a ListBox to a collection of objects, but I want to display one of the object’s fields, and also somehow to attach a Guid (another field) to each item. Could you please tell me how I can do that? I don’t know if Caliburn.Micro has something specific for it, or I just have to use WPF.

Thanks.

Answer 1

(sorry for my bad english)

If the Guid field is part of your object, you do not need to store it on another place. The listbox will show a field but it is still bounded to the original object, you can get it with ((MyObjectType)MyListBox.SelectedItem).Guid. With Caliburn it is even easier since you just need to bind a property on your VM to SelectedItem.

But if the Guid is not part of your object, you can use the Tag property, as Paul Sasik said. I do not like to use the Tag property so this is another easy (and more flexbible) way you can solve this, you need to encapsulate your object on another object:

public class GuidObject<T>
{
    public T Instance {get;set;}
    public Guid Guid {get;set;}
}

You can use it like this:

//this is your original guidless items list
var myObjectsList = new[] { new MyObject { Name = "Dostoyevsky" }, 
                            new MyObject { Name = "Ozzy" } };

var myObjectsWithGuidList = new ObservableCollection<GuidObject<MyObject>>();

//encapsulate each MyObject on a GuidObject and include a Guid
//if your myObjectsList is already a List, you do not need to call ToList()
myObjectsList.ToList().ForEach(o => myObjectsWithGuidList.Add(new GuidObject<MyObject>() { Instance = o, Guid = Guid.NewGuid() }));

//now myObjectsWithGuidList contains a list of your itens and a Guid field, you can bind it to your ListBox

Here you can see this running.