Tag Archives: Asp.Net

C# – Abstract Class vs Interface

Biswajeet   September 13, 2015   No Comments on C# – Abstract Class vs Interface

Abstract Class:

  • An abstract class is one that is intended only to be a base class of other classes, and the “abstract” modifier is used to make a class abstract. An abstract class cannot be a sealed class. An abstract method cannot be private. The access modifier of the abstract method should be same in both the abstract class and its derived class. An abstract method cannot have the modifier virtual. Because an abstract method is implicitly virtual.
  • An abstract class can have abstract members as well non abstract members.
  • It can have constants, read only variables, instance variables and static variables.
  • We cannot create an object of abstract class.
  • Abstract class contains Constructors.
  • Only Complete Member of abstract class can be Static.
  • A class can inherit only one abstract class.
  • A class inheriting an abstract class has to override the abstract methods from abstract class while implementing them.
  • We go for Abstract classes on such situations, When we have a requirement where our base class should provide default implementation of certain methods whereas other methods should be open to being overridden by child classes use abstract classes.

Interface:

  • An interface is an entity that is defined by the word Interface, it is not a class. An interface contains only the signatures of methods. Interface members cannot have any access specifier like public, private, protected, internal or protected internal. By default all the members of an interface are Public.
  • In an interface all the members are implicitly abstract.
  • It cannot have member variables.
  • We can create an object of interface by type casting it to class name.
  • Interface doesn’t contains Constructors.
  • Member of interface can not be Static.
  • A class can implement any number of Interfaces.
  • A class implementing an interface has to implement all the methods of the interface compulsorily.
  • We go for Abstract classes on such situations, If our child classes should all implement a certain group of methods but each of the child classes is free to provide its own implementation then use interfaces.

These are the basic differences between abstract class and interface.

CSV Helper

Biswajeet   March 25, 2014   No Comments on CSV Helper

A .NET library for reading and writing CSV files. Extremely fast, flexible and easy to use. Supports reading and writing of custom class objects.

The first thing to do is to Install CsvHelper.
To install CsvHelper, run the following from the Package Manager Console.

Install-Package CsvHelper 

Now add CsvHelper to the program by adding:

using CsvHelper;

The next step is to create a class which has properties with the same name of the column headings found in the csv file.  Below you will find an example of a class which does this:

public class Customer
{
    public string Name { get; set; }
    public string Address { get; set; }
    public string PhoneNo { get; set; }
    public string Country { get; set; }
}

Finally create an instance of CSVReader and invoke the GetRecords method using the DataRecord class. Below you will find an example of this:

using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using CsvHelper;
namespace CSVHelperReadSample
{
    internal class Program
    {
       private static void Main(string[] args)
       {
          using (var sr = new StreamReader(@"Customerlist.csv"))
          {
             var reader = new CsvReader(sr);

             //CSVReader will now read the whole file into an enumerable
             IEnumerable<datarecord> records = reader.GetRecords<customer>();

             //First 5 records in CSV file will be printed to the Output Window
             foreach (DataRecord record in records.Take(5))
             {
                 Debug.Print("{0} {1}, {2}, {3}", record.Name, record.Address, record.PhoneNo, record.Country);
             }
         }
      }
   }
}

Static Constructor

Biswajeet   March 15, 2014   No Comments on Static Constructor

A static constructor is used to initialize any static data, or to perform a particular action that needs performed once only. It is called automatically before the first instance is created or any static members are referenced.

Static constructors have the following properties:

  • A static constructor does not take access modifiers or have parameters.
  • A static constructor is called automatically to initialize the class before the first instance is created or any static members are referenced.
  • A static constructor cannot be called directly.
  • The user has no control on when the static constructor is executed in the program.
  • A typical use of static constructors is when the class is using a log file and the constructor is used to write entries to this file.
  • Static constructors are also useful when creating wrapper classes for unmanaged code, when the constructor can call the Load Library method.
  • You can’t overload it.