what is delegate

MD SHAMSE ALAM

11y1kVisual Basic .NET

what is delegate

6 Replies

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Munesh Sharma11y ago
http://www.tutorialspoint.com/csharp/csharp_delegates.htm
Sujeet Suman11y ago
Delegate is a type which works like a type safe function pointer.

There are 3 steps to create a delegate:
Declaration
Instrantiation
Invocation

There are 3 types of delegate:
Singlecast delegate
Multicast delegate
Generic delegate

By the help of BeginInvoke() and EndInvoke() we can call a method asynchronously.
Upendra Pratap Shahi11y ago
http://www.codeproject.com/Articles/772792/Delegates-and-Types-of-Delegates-in-Csharp

http://www.tutorialspoint.com/csharp/csharp_delegates.htm

http://csharpindepth.com/Articles/chapter2/events.aspx
Rajeesh Menoth11y ago
Hi,

What is the use of Delegates?
Suppose if you have multiple methods with same signature (return type & number of parameters) and want to call all the methods with single object then we can go for delegates.
Delegates are two types
- Single Cast Delegates
- Multi Cast Delegates
Single Cast Delegates
Single cast delegate means which hold address of single method like as explained in above example.
Multicast Delegates

Multi cast delegate is used to hold address of multiple methods in single delegate. To hold multiple addresses with delegate we will use overloaded += operator and if you want remove addresses from delegate we need to use overloaded operator -=
Multicast delegates will work only for the methods which have return type only void. If we want to create a multicast delegate with return type we will get the return type of last method in the invocation list

More details ref this following links :

1) http://stackoverflow.com/questions/2019402/when-why-to-use-delegates

2) http://www.aspdotnet-suresh.com/2013/09/C-Sharp-delegates-example-use-of-delegates-in-C-Sharp.html
Manoj Bhoir11y ago
Hi,

A delegate is a type that represents references to methods with a particular parameter list and return type. When you instantiate a delegate, you can associate its instance with any method with a compatible signature and return type. You can invoke (or call) the method through the delegate instance.
Delegates have the following properties:

Delegates are like C++ function pointers but are type safe.

Delegates allow methods to be passed as parameters.

Delegates can be used to define callback methods.

Delegates can be chained together; for example, multiple methods can be called on a single event.

Methods do not have to match the delegate type exactly. For more information, see Using Variance in Delegates (C# and Visual Basic).

For more details please check these links :
https://msdn.microsoft.com/en-us/library/ms173171.aspx
http://www.tutorialspoint.com/csharp/csharp_delegates.htm
http://www.codeproject.com/Articles/772792/Delegates-and-Types-of-Delegates-in-Csharp
http://www.codeproject.com/Articles/11657/Understanding-Delegates-in-C
Santhakumar Munuswamy11y ago
HI,

Read this below link
http://www.codeproject.com/Articles/772792/Delegates-and-Types-of-Delegates-in-Csharp
http://www.codeproject.com/Articles/11657/Understanding-Delegates-in-C