static void Main(string[] args)
{
LinqExample.main();
CollectionExample.main();
DelegateExample.main();
StringBuilderExample.main();
DisposeExample.main();
ReferencesExample.main();
Customer.main();
Console.WriteLine("All done");
}
public static void main()
{
// The word delegate is often confusing used to describe both the delegate type and the delegate instance.
// But the distinction between the two is exactly the same as between any other type and instances of that type.
// STEP THREE: CREATE AN INSTANCE OF THE DELEGATE TYPE, SPECIFYING WHICH METHOD (THE ACTION) WILL BE EXECUTED WHEN THE DELEGATE INSTANCE IS INVOKED.
StringProcessor sp1 = new StringProcessor(doSomething);
// When the ACTION in an instance method, you need an instance of the type. This object instance is called the TARGET of the ACTION.
// When the delegate instance is invoked, the ACTION will be invoked on the TARGET.
// A delegate instance will prevent its target from being garbage collected if the delegate instance itself is collected.
// This will result in memory leaks: a long-lived object indirectly holds a reference to short-lived one, prolonging its lifetime.
DelegateExample de = new DelegateExample();
StringProcessor sp2 = new StringProcessor(de.doSomethingElse);
// STEP FOUR: INVOKE THE DELEGATE INSTANCE
Console.WriteLine("Invoking delegate instance sp1 returns {0}", sp1.Invoke("leon"));
// Invoking a delegate without using an explicit call of the Invoke method.
Console.WriteLine("Invoking delegate instance sp2 returns {0}", sp2("LEON"));
sp2 += sp1;
Console.WriteLine("Invoking multicasted delegate instance sp2 returns {0}", sp2("LEON"));
StringProcessor sp3 = new StringProcessor(de.doSomethingElse);
}