Add empty entry to combobox bound to entity list

Question

I use a ComboBox which is bound to a List<> of Entities. How can I add a "Not selected" entry to the combobox? Adding null to the list results in empty combobox.

Answer 1

You should use an empty string or other unique text pattern instead of null.

And then You can handle the Format event of the Combobox to intercept the <empty> and display an alternate text.

private void comboBox1_Format(object sender, ListControlConvertEventArgs e)
{
   e.Value = FormatForCombobox(e.ListItem);
}


private string FormatForCombobox(object value)
{
  string v = (string) value;
  if (v == string.Empty)
     v = "<no Selection>";
  return v;
}