When to Use Structure?

When to Use Structure?

Do not define a structure unless the type has all of the following characteristics:

-It logically represents a single value, similar to primitive types (integer, double, and so on).

-It has an instance size smaller than 16 bytes.

-It is immutable[whose state cannot be modified after it is created].

-It will not have to be boxed frequently.

When to Use Delegates Instead of Interfaces ?

When to Use Delegates Instead of Interfaces ?

Both delegates and interfaces allow a class designer to separate type declarations and implementation. A given interface can be inherited and implemented by any class or struct;

A delegate can created for a method on any class


Use a delegate when:

-An eventing design pattern is used.

-It is desirable to encapsulate a static method.

-The caller has no need access other properties, methods, or interfaces on  the object implementing the method.

-Easy composition is desired.

-A class may need more than one implementation of the method.

Use an interface when:

There are a group of related methods that may be called.

A class only needs one implementation of the method.

The class using the interface will want to cast that interface to other interface or class types.

The method being implemented is linked to the type or identity of the class: for example, comparison methods.

When to Use Inheritance ?

Inheritance is a good choice when:

• Your inheritance hierarchy represents an "is-a" relationship and not a "has-a" relationship.
• You can reuse code from the base classes.
• You need to apply the same class and methods to different data types.
• The class hierarchy is reasonably shallow, and other developers are not likely to add many more levels.
• You want to make global changes to derived classes by changing a base class.

• Composition – Composition is used when the two class has-a relationship among classes
  Inheritance – Inheritance is used when the derived class is-a relationship base class
  
  
  For example :
  Take two class
  1.House owner
  2.House
  
  
  House owner is a House is not valid - Inheritance
  House owner has a house is valid - Composition
  
  
  For example :
  Take two class
  1.Game
  2.Cricket
  
  
  
  
  Cricket is a game is valid - Inheritance
  Cricket has a game is invalid - Composition

Empty all table values in the Database

Empty all table values in the Database

CREATE PROCEDURE SP_EmplyAllTableValues
AS
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
EXEC sp_MSForEachTable 'DELETE FROM ?'
EXEC sp_MSForEachTable 'ALTER TABLE ? CHECK CONSTRAINT ALL'
GO

exec SP_EmplyAllTableValues

Stack and Queue Realtime example and System Example:

Stack and Queue Realtime example and System Example:

Queuing Example[FIFO]

System  : Message Queue - MSMQ
Real Time:The bullet in a machine gun

Stack Example[LIFO]

System : Memory Allocation in System
Real Time:The tennis balls in their container

File Creation Date and Time Conversion in C#

File Creation Date and Time Conversion in C#


using System;
using System.IO;
using System.Windows.Forms;

namespace ConvertDataTime
{
    public partial class ConvertDataandTime : Form
    {
        public ConvertDataandTime()
        {
            InitializeComponent();
        }

   
        private void btnConvert_Click(object sender, EventArgs e)
        {
            try
            {
                //"08/26/2011 15:00:00"
                FileSystemInfo f = new FileInfo(@txtPath.Text);
                f.CreationTime = Convert.ToDateTime(txtDateTime.Text);
                f.LastWriteTime = Convert.ToDateTime(txtDateTime.Text);
                f.LastAccessTime = Convert.ToDateTime(txtDateTime.Text);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            txtDateTime.Text = "08/26/2011 15:00:00";
            txtPath.Text="D:\\";
        }

     

     
    }
}

Composition vs Inheritance in OOPS

 Composition vs Inheritance in OOPS

Composition – Composition is used when the two class has-a relationship among classes

Inheritance – Inheritance is used when the derived class is-a relationship base class

For example :

Take two class

1.House owner

2.House

House owner is a House is not valid - Inheritance

House owner has a house is valid - Composition

For example :

Take two class

1.Game

2.Cricket

Cricket is a game is valid - Inheritance

Cricket has a game is invalid - Composition