A delegate contains a reference to a method rather than the method name itself. By using delegates, you can decide which method to call at runtime. It is also possible to call a method without actually knowing its name. Executing (or calling) a delegate will, in turn, execute the method that it references.
for example, consider two methods SumMe() and DiffMe(). SumMe() takes in two integer type parameters, and returns the sum of the numbers as another integer type. Similarly, DiffMe() takes in two integer type parameters, subtracts the second from the first and returns the result in the form of integer. Since both the methods take in the same type and number of parameters and both return an integer, a delegate (called DeleMe) can be created, Which at times could be made made to point to SumMe() and at times to DiffMe(). When Delegate points to SumMe() and is called, the parameters passed would be added. However, if it is called while being pointed to DiffMe(),then the subtracted result of the parameters passed gets returned.
I think three steps involved in using delegates that are as follows:
1. Defining a delegate
Example: public delegate void DelegateName();
2. Instantiating a Delegate: means making it point or refer to some method. After a delegate is defined, it must be instantiated.
Example:
--------
public delegate int DeleMe(int a, int b);
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3. Using a Delegate: Means instantiating a method using delegates. A delegate is called in the same way as method is called. The only difference is that instead of calling the delegate implementation, the implementation code of the method associated with the delegate is called.
example:
class TestDelegates
{
public delegate int DeleMe(int a, int b);
class Maths
{
public int SumMe(int a, int b);
{
return a+b;
}
public int DiffMe(int a, int b);
{
return a-b;
}
}
class Test
{
static void Main()
{
DeleMe DelegateObj;
Maths m= new Maths();
DelegateObj = new DeleMe(m.SumMe);
int t=DelegateObj (5,3);
System.Console.WriteLine("The Result is:{0}",t);
}
}
I think its clear. so what will be the output.
output:
The Result is : 8
so how it will for difference? try in the code also and if problem tell me.
}
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| Author: Mahesh Raj 07 Jun 2008 | Member Level: Gold Points : 1 |
This is very good information,Continue posting such useful articles.
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| Author: John Fernandez 08 Jun 2008 | Member Level: Gold Points : 1 |
Very well written Article.Thanks for sharing this information.
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| Author: antogladwin 17 Jun 2008 | Member Level: Silver Points : 1 |
hi Ravindra,
it is very helpfull information 2 all.keep it up...continue posting Articles like this......
BY,
R.A.Gladwin
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| Author: Kapil Dhawan 17 Jun 2008 | Member Level: Gold Points : 2 |
Hello
Nice piece of code
Thanks for sharing your knowledge with us.
I hope to see more good code from your side
Very Good Info for all of us.
thanks ton to you
Regards,
Kapil
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| Author: Gaurav Agrawal 18 Jun 2008 | Member Level: Silver Points : 2 |
Hi Ravindra,
Nice article.
Your article is very helpful to understand the concept of delegate.
It was really confusing but it is clear now.
Please keep posting and help your fellow developers.
Happy programming.
Thanks
Gaurav Agrawal
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