Question

I am implementing Key Navigation for an application and I want to override the space key functionality when a Combo Box is focused such that it acts like an enter key; like this:

if (!cb.IsDropDownOpen)
{
  cb.IsDropDownOpen = true;
}
else
{
  cb.SelectedItem = cb.{non-public member HighlightedItem};
  cb.IsDropDownOpen = false;
}

The problem is that I need to get the value of that non-public member so that I can set the selected value and close the drop-down (how enter would normally work).

Now the question is: What is the fastest and hassle free way of achieving this?

Answer 1

You’d have to use reflection to get the value of the property

PropertyInfo highlightedItemProperty = cb.GetType().GetProperties(BindingFlags.NonPublic  | BindingFlags.Instance).Single(pi => pi.Name == "HighlightedItem");
object highlightedItemValue = highlightedItemProperty.GetValue(cb, null);

To browse all properties or fields, also check out

var allProps = cb.GetType().GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance).OrderBy(pi => pi.Name).ToList();
var allFields = cb.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance).OrderBy(pi => pi.Name).ToList();

(you can read through them all in the debugger)