Delegate, DOT NET Programming

Assignment Help:

What is a delegate?

The Delegate is the class that can hold a reference to a method or a function. The Delegate class has a signature and it can only reference to those methods whose signature is compliant with the class. The Delegates are type-safe functions pointers or callbacks.

The sample code is shown below which shows an example of how to implement delegates.

Public Class FrmDelegates

Inherits System.Windows.Forms.Form

Public Delegate Sub DelegateAddString()

Private Sub FrmDelegates_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

End Sub

Private Sub AddString()

lstDelegates.Items.Add("Running AddString() method") End Sub

Private Sub cmdDelegates_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdDelegates. Click

Dim objDelegateAddString As DelegateAddString objDelegateAddString = AddressOf AddString objDelegateAddString.Invoke()

End Sub

End Class

In the above code there is a method called "AddString()" that adds a string to a listbox. You can also view a delegate declared as:-

Public Delegate Sub DelegateAddString()

This delegate signature is compatible with all the "AddString" method. When I say compatibility that means that there return types and passing parameter types are similar. After in command click of the button object of the Delegate is created and the method pointer is received from "AddressOf" keyword. Then by using "Invoke" method the method is invoked.

 

668_delegate.png

Figure:-Delegate in Action


Related Discussions:- Delegate

Which property on a combo box do you set with a column name, Which property...

Which property on a Combo Box do you set with a column name, prior to setting the Data Source, to display data in the combo box? ComboBox.DataValueField = "ColumnName" When

Different types of jit, JIT compiler is the part of the runtime execution e...

JIT compiler is the part of the runtime execution environment. In Microsoft .NET there are three types  of JIT compilers are available: 1) Pre-JIT :- The Pre-JIT compiles the co

DESIGN CALENDAER, HOW TO DESIEN THE CALENDER IN ASP . NET

HOW TO DESIEN THE CALENDER IN ASP . NET

Prepare one web based application, I want to prepare one web based applicat...

I want to prepare one web based application which have student registration and according to semester and every time it will change as per semester change according, now student ge

I need online real commission management system, I need Online Real Commiss...

I need Online Real Commission Management system Project Description: Real Estate -- Store and retrieve Purchase plot customers, Employee to refer the customers get commiss

Reading strings from the keyboard, Reading strings from the keyboard   ...

Reading strings from the keyboard   using System; class Prog3_1 {       public static void Main()   {    Console.Write ("Enter Your First Name : "); // Displaying to writ

I want high skilled c++ programmers, I want high skilled C++ programmers ...

I want high skilled C++ programmers Project Description: I want to hire the developer, who are proficient in C/C++ and have experience with STL and work with the data structu

What is a gateway, What is a gateway or Router? A node that is linked t...

What is a gateway or Router? A node that is linked to two or more networks is commonly called as router or Gateway. It generally forwards message from single network to another

Windows application for ildasm application, In this assignment you will cre...

In this assignment you will create a Windows application that mimic the ILDASM application. Your application should have at least the following features: 1. A multi-form applica

Vb 2010, how to create log in form using vb 2010

how to create log in form using vb 2010

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd