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Multicast Delegates
A multicast delegate has a linked list of delegates,
called an invocation list, consisting one or more elements. When a multicast
delegate is invoked, the delegates in the invocation list are called
synchronously in the order which they appear of. An error occurs during
execution of the list then on exception is thrown.
using
System;
namespace
AStepAhead.MulticastDelegate
{
public
delegate void DelString(string str);
public
class MulticastDelegate
{
public static void firstMethod(string x)
{
Console.WriteLine("It prints using first method.\nYou have entered:{0}", x);
}
public static void secondMethod(string y)
{
Console.WriteLine("\nIt prints using second method.\nYou have entered:{0}",
y);
}
public static void thirdMethod(string z)
{
Console.WriteLine("\nIt prints using third method.\nYou have entered:{0}",
z);
}
static void Main(string[] args)
{
Console.Clear();
Console.Write("Enter string : ");
string str = Console.ReadLine();
DelString myMultiDel1, myMultiDel2, myMultiDel3, myMultiDel4, myMultiDel5;
//Firs call method individually
myMultiDel1 = new DelString(firstMethod);
myMultiDel1(str);
Console.ReadLine();
myMultiDel2 = new DelString(secondMethod);
myMultiDel2(str);
Console.ReadLine();
myMultiDel3 = new DelString(thirdMethod);
myMultiDel3(str);
//Combine two delegates or multicast
Console.WriteLine("\nThis all using Multicast delegates\n");
myMultiDel4 = myMultiDel1 + myMultiDel2 + myMultiDel3;
myMultiDel4(str);
//another way to multicast
Console.WriteLine("\nThis all using Multicast delegates showing another way of
multicasting\n");
myMultiDel5 = new DelString(firstMethod);
//multicasting or combining / attaching
myMultiDel5 += new DelString(thirdMethod);
myMultiDel5(str);
//deattaching
myMultiDel5 -= new DelString(firstMethod);
myMultiDel5(str);
Console.ReadLine();
}
}
}
Anonymous method
In Anonymous method, we can write the entire code-block
of a method within delegate like a parameter. It eliminates the need to create a
separate method.
The Scope of the parameters of an anonymous method is in
the anonymous method-block only. In an anonymous method, the use of jump
statements like goto, break or continue are not allowed whose target is outside
the anonymous method block. It cannot access the ‘ref’ or ‘out’ parameters of an
outer scope. Moreover, no unsafe code can be accessed within the anonymous
method block.
using System;
namespace
AstepAhead.anonymousmethod
{
public class
delegateClass
{
public delegate
void delegateAdd(int x, int y);
public static void
Main()
{
delegatelass
mydelcls = new delegateAdd();
mydelcls.delAdd
mydellAdd = new mydelcls.delAdd(int a, int b)
{
Cosole.WrieLine(“Sum of {0}, {1} = {2}”, a,b, b+a);
}; //anonymous block
Console.WriteLine(“Enter first
number : “);
Int num1=
int.parse(Console.ReadLine());
Console.WriteLine(“Enter second
number : “);
Int num2=
int.parse(Console.ReadLine());
//Invoke named method
myAddDel(num1, num2);
Console.ReadLine();
}
}
}
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