public void cast_error() {
// cast will pass compiler, but result a runtime error if wrong cast
// e.g. cast Frank to Hexgan, (Hexgan)frant
object frank = new Manager();
Hexagon hex;
try {
hex = (Hexagon) frank;
} catch (InvalidCastException ex) {
Console.WriteLine( ex.Message);
}
}
public void as_operator () {
// trail cast, if not compatible, return null
// Use "as" to test compatability.
object[] things = new object[ 4];
things[ 0] = new Hexagon();
things[ 1] = false;
things[ 2] = new Manager();
things[ 3] = "Last thing";
foreach (object item in things) {
Hexagon h = item as Hexagon;
if (h == null)
Console.WriteLine(" Item is not a hexagon");
else { h.Draw();
}
}
}