Creates a new collection using the items in itemsString as elements.
            
| C# | Visual Basic | Visual C++ | 
public FileTypeCollection( string itemsString )
Public Sub New ( _ itemsString As String _ )
public: FileTypeCollection( String^ itemsString )
- itemsString (String)
 - String formatted as; item1EXTENSION-item1MIME,item2EXTENSION-item2MIME