Binding editor to multiple properties

Hi Mick,

You can access the underlying object using something like "{Binding DataContext.Target, RelativeSource={RelativeSource AncestorType={x:Type propgrid:PropertyGridDataAccessorItem}}}". So if the object has the list of valid values, then you can bind to it like "{Binding DataContext.Target.SubValues...".

Otherwise, you could bind ItemsSource to the Category property and use a custom IValueConverter to return one list of values or other.

Thank you,

The object that I am trying to bind to does not have a list of valid values. It is a "dumb" object that only knows 2 string fields - "category" and "subcategory." The list of valid values will get populated by a service call that my BO has no knowledge of.

When I try to bind the ItemsSource of my ComboBox, I get the following error:

InvalidOperationException : A TwoWay or OneWayToSource binding cannot work on the read-only property 'Target' of type 'ActiproSoftware.Windows.Controls.PropertyGrid.Primitives.PropertyDescriptorDataAccessor'.

A OneWay binding works just fine, but causes the problem that when I update the "Category" (main) property, it does update the "SubCategory" property when changed.

Because I want the source for the "SubCategory" box to change based on the "Category" box, a two way binding seems necessary.

How do I get around this?

After reading my post, I realize that I may have opened the door to you offering a solution using the binding:

"{Binding DataContext.Target.Category" (this will presumably not throw the error above, because "Category" is not a readonly property)

to get the "SubCategory" ItemsSource to refresh.

However, the "SubCategory" dropdown might change based on the state of the entire object, not just the "Category" property, so I'm not sure, but I don't believe this will be a viable solution.

Thank you,
Mick

Hi Mick,

I'm not entirely sure what you are trying to do. You would need to bind the ItemsSource to a list of potential values, but there are several ways to do this. You do not want this to be a TwoWay binding or a OneWayToSource, as you should define the binding on the ItemsSource property and do not what it's changes passed back.

You would either need to expose the potential values on your object or use a MultiBinding and a custom IMutliValueConverter. In the former case, your combine all the values that determine the potential values in your object. In the latter case the IMultiValueConverter does it, but you'd need to bind to ever property that determines the potential list of values.

Hello,

Thank you for your quick response.

Mick

[Modified at 02/28/2011 04:51 PM]