Display multiple types from a single list in a WPF ListBox?

Answer 1

You have to use a DataTemplateSelector. See here for an example.

Addiontal information on MSDN

Answer 2

You say that "it claims it can't find my types." That's a problem that you should fix.

The problem, most likely, is that you're not creating a namespace declaration in the XAML that references your CLR namespace and assembly. You need to put something like this in the XAML's top-level element:

xmlns:foo="clr-namespace:MyNamespaceName;assembly=MyAssemblyName"

Once you do this, XAML will know that anything with the XML namespace prefix foo is actually a class in MyAssemblyName in the MyNamespaceName namespace.

Then you can reference that XML namespace in the markup that created the DataTemplate:

<DataTemplate DataType="{foo:Person}">

You can certainly build a template selector, but that's adding a piece of cruft to your software that doesn't need to be there. There's a place for template selectors in WPF applications, but this isn't it.