//Classic sample of Polymorphism 4 Knowing When to Use Override and New Keywords
public static void ScenarioEight()
{
Teacher baseTeacher = new Teacher();
baseTeacher.ShowMeDance();
System.Console.WriteLine("----------");
NewStyleTeacher newStyleTeacher = new NewStyleTeacher();
newStyleTeacher.ShowMeDance(); //go to the new
newStyleTeacher.Dance(); ///go to the new
System.Console.WriteLine("----------");
BachataTeacher bachataTeacher = new BachataTeacher();
bachataTeacher.ShowMeDance(); //go to base
System.Console.WriteLine("----------");
StupidTeacher stupidTeacher = new StupidTeacher();
stupidTeacher.ShowMeDance(); //go to the old
// Keep the console open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
//Classic sample of Polymorphism 3
// If you want your derived member to have the same name as a member in a base class, but you do not want it to participate in virtual invocation,
// you can use the new keyword.The new keyword is put before
// the return type of a class member that is being replaced.The following code provides an
public static void ScenarioSix()
{
NewStyleTeacher B = new NewStyleTeacher();
B.Dance(); // Calls the new method.
Teacher A = (Teacher)B;
A.Dance(); // Calls the old method.
// Keep the console open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
//Calls with cast implicit Knowing When to Use Override and New Keywords
// "new" keyword is specified, the compiler will issue a warning and the method
//in the derived class will hide the method in the base class.
public static void ScenarioNine()
{
var derived = new NewStyleTeacher();
derived.Dance();
((Teacher)derived).Dance(); //Call old method-----new
System.Console.WriteLine("----------");
var derived2 = new BachataTeacher();
derived2.Dance();
((Teacher)derived2).Dance(); //Call new method-----------override
// Keep the console open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
//Classic override with "new" witout override
public static void ScenarioFive()
{
NewStyleTeacher teacher = new NewStyleTeacher();
teacher.Dance(); // Show Child
teacher.ShowMeDance(); // Show Father
Console.WriteLine("------------------");
Teacher newTeacher = (Teacher)teacher;
newTeacher.Dance();
newTeacher.ShowMeDance(); // Show father -public virtual void Dance()
Console.WriteLine("------------------");
((Teacher)teacher).Dance();
// Keep the console open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}