Question

I have this following function in C++ CLI:

void receiveData(String^ data)
{

}

From C# I call the function like this:

if (e.OriginalSource is ComboBox)
{
  ComboBox combo = e.OriginalSource as ComboBox;
  if (combo.SelectedItem != null)
  {
      receiveData(combo.SelectedItem as string);
  }
}

But inside the function the string parameter is always undefined.
What is the correct way to pass the SelectedItem as string to my function ?

Thanks.

Answer 1

SelectedItem returns the selected object. If you want the text, use SelectedItem.ToString(). But watch out for nulled selected items, this might be better:

string selectedText = combo.SelectedItem == null ? string.Empty  : combo.SelectedItem.ToString()

If you do not add strings to the items list, you will get null when you use the as operator on a variable and try to cast it to a type that it isn’t.