title: Is it possible to specify an array type as the ExpressionType for an ExpressionTextBox in a Workflow Activity Designer? If so, how?
body: <p>I'm trying to write a custom activity designer for Windows Workflow that allows the user to bind an activity parameter in the design window (as opposed to using the Visual Studio properties dialog). Normally, I'd just write something like this:</p>
  
  <pre><code>&lt;sapv:ExpressionTextBox Grid.Row="0" Grid.Column="1" OwnerActivity="{Binding Path=ModelItem}" Expression="{Binding Path=ModelItem.Strings, Mode=TwoWay, Converter={StaticResource ArgumentToExpressionConverter}, ConverterParameter=In}" ExpressionType="??s:String[]??" HintText="The strings to combine." /&gt;
  </code></pre>
  
  <p>The problem in this case (as can be seen in the above) is that I don't know what the <code>ExpressionType</code> should be for an array type. Assuming a namespace specification of <code>xmlns:s="clr-namespace:System;assembly=mscorlib"</code>, for a string, it would be <code>s:String</code>. Is it possible to do the same thing for a string array? And if so, how please?</p>