Instantiate ItemsPanelTemplate

Question

I'm trying to create a ItemsControl that has a separator between items, for example a control to create a navigation bread crumb. I want the control to be completely generic.

My original method was to create extend ItemsControl, add a SeparatorTemplate property, and then have the class add separators to the ItemsHost of the ItemsControl. The problem with this approach is that if you add extra items to the container panel, the ItemGenerator gets confused and the items are out of order and don't get removed correctly.

So my second plan was to create a completely new control that would emulate an ItemsControl, but the problem I'm running into is that I can't find a way to instantiate an ItemsPanelTemplate. I would like to provide an ItemsPanel property just like ItemsControl, but I can't then create a panel from that template.

Can anyone think of a way to either instantiate an ItemsPanelTemplate or way to add controls to an ItemsControl's panel without breaking the ItemGenerator?

Answer 1

Well I haven't tried it myself but I would have thought you would override the GetContainerForItemOverride to acheive this.

You could create a new BreadCrumbItem control which is a templated ContentControl that has in its default template the typical ContentPresenter and whatever you want to use by default as separator all in a Grid or StackPanel.

The GetContainerForItemOverride generates a new instance of this BreadCrumbItem sets its ContentTemplate to the ItemTemplate property from your ItemsControl derivative (the BreadCrumb control?).

Your BreadCrumb control would also expose BreadCrumbItemStyle property that you assign to the BreadCrumbItem you create during GetContainerForItemOverride.

For completeness you may need to also implement the other *Container*Override methods in your BreadCrumb control.