ASP.net MVC 5 Life cycle

Data Type In c#

Data Types

Data Types define the type of data that a variable can store. Some variables store numbers, others store names. The built-in VB.NET type aliases and their equivalent .NET Framework types follow:

Integers

VB Alias	.NET Type	Size	Range
SByte	System.SByte	8 bits (1 byte)	-128 to 127
Byte	System.Byte	8 bits (1 byte)	0 to 255
Short	System.Int16	16 bits (2 bytes)	-32,768 to 32,767
UShort	System.UInt16	16 bits (2 bytes)	0 to 65,535
Integer	System.Int32	32 bits (4 bytes)	-2,147,483,648 to 2,147,483,647
UInteger	System.UInt32	32 bits (4 bytes)	0 to 4,294,967,295
Long	System.Int64	64 bits (8 bytes)	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
ULong	System.UInt64	64 bits (8 bytes)	0 to 18,446,744,073,709,551,615

Floating-point

VB Alias	.NET Type	Size	Precision	Range
Single	System.Single	32 bits (4 bytes)	7 digits	1.5 x 10-45 to 3.4 x 1038
Double	System.Double	64 bits (8 bytes)	15-16 digits	5.0 x 10-324 to 1.7 x 10308
Decimal	System.Decimal	128 bits (16 bytes)	28-29 decimal places	1.0 x 10-28 to 7.9 x 1028

Other pre-defined types

VB Alias	.NET Type	Size (bits)	Range
Char	System.Char	16 bits (2 bytes)	One Unicode symbol in the range of 0 to 65,535.
Boolean	System.Boolean	32 bits (4 bytes)	True or False
Object	System.Object	32/64 bits (4/8 bytes)	Platform dependent (a reference to an object).
Date	System.DateTime	64 bits (8 bytes)	January 1, 0001 12:00:00 AM to December 31, 9999 11:59:59 PM
String	System.String	80 + [16 * Length] bits (10 + [2 * Length] bytes)	A Unicode string with a maximum length of 2,147,483,647 characters.

 

Value Types

·         All numeric data types

·         Boolean, Char, and Date

·         All structures, even if their members are reference types

·         Enumerations, since their underlying type is always SByte, Short, Integer, Long, Byte, UShort, UInteger, orULong

Reference Types

·         String

·         All arrays, even if their elements are value types

·         Class types, such as Form

·         Delegates

Elements That Are Not Types

·         Namespaces

·         Modules

·         Events

·         Properties and procedures

·         Variables, constants, and fields

 

Collection - Still working on... ! :)

Collections	Dynamic Array	Fast lookup	Required Cast	Good Choice for Booleans	Thread safety	Stores Any type object	Linear Array	Loop	Comments
List	Yes	Not good	No	No	no	No(Except List<object> )	Yes	It is fast because it is Linear
Dictionary	Yes	Yes	No	No	No
ArrayList	yes	No	Yes	No	No	Yes	Yes
Hashtable		Yes							It is an older .NET Framework type.
ConcurrentDictionary	Yes	Yes	No	No	Yes	No
ConcurrentBag									Sometimes lookup functionality is not required. ConcurrentBag allows us to safely Add and Take results
BitArray				yes					The program creates a bool array with true and false values, and then the BitArray constructor converts those into one bit each. This means that instead of one byte for a bool, the values are stored as one bit, in one-eighth the space.
Tuple									A Tuple has many items. Each item can have any type. The Tuple class provides a unified syntax for creating objects with typed fields.
KeyValuePair									Tuple was faster in every test than KeyValuePair except in allocation performance.
Stack
Queue
HashSet									HashSet is an optimized set collection. It helps eliminates duplicate strings or elements in an array. It provides a simple syntax for taking the union of elements in a set. This is performed in its constructor. Constructor   Example. This program contains a source array that contains several duplicated strings. It eliminates duplicate strings in the array. The program calls the HashSet constructor to transform the array elements into a set data structure.   When the source input becomes large with thousands of elements, hashed collections are faster.
SortedSet									SortedSet is an ordered set collection. We have many elements and want to store them in a sorted order and also eliminate all duplicates from the data structure. The SortedSet is part of the System.Collections.Generic namespace.
Lazy									This type implements the lazy instantiation pattern. We look into the concept of thunks, as described in a programming textbook. The Lazy class has no relation to the Sleep method.
HybridDictionary									HybridDictionary attempts to optimize Hashtable. It implements a linked list and hash table data structure, switching over to the second from the first when the number of elements increases past a certain threshold.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                                                                                                                                                                                                                                                        

Search a string in SQL Stored Procedure

DECLARE @Search varchar(255)

SET @Search='COMPLETE'

 

SELECT DISTINCT

    o.name AS Object_Name,o.type_desc,m.definition

    FROM sys.sql_modules        m

        INNER JOIN sys.objects  o ON m.object_id=o.object_id

    WHERE m.definition Like '%'+@Search+'%'

    ORDER BY 2,1

Genarate Links on View in MVC

It's always  better to  generate a URL using “Url. Action” method to avoid URL issues. When Deploying application from one environment to other environments, it may not necessary to have a same website configuration on IIS. Means, On development you may have a virtual directory structure is “www.test.com/application/results” but in other environments, it configured as ““www.test.com/websitename/application/results” so we need to consider all these Directory structures when we are generating URL otherwise we run into issues. URL. Action method will take care of these things so it is a good idea to  use URL. Action method to avoid URL issues   

  

Example: Url.Action("results", "Application", new { id = Model.id })                                                                                         

 

 

 

 

 

 

 

 

 

 

 

                                                                                                                                                                      

Custome validations in MVC

Validations are very important in any application  and Validations restrict the invalid data being entered into the application.

In MVC we can build a custom validations framework by extending “ValidationAttribute”, “IClientValidatable”.

 

The “ValidationAttribute“ class serves as base class for all  validations  and  By overriding “Isvalid” method we can  extend the validations.

The ValidateAttribute take two parameters value and the Validation context which holds all the control values.

 

For example I want to compare   two dates.

 

Create a class with extends the validation attribute and create a property of compare to date field name. using validation Context, retrieve the value the compare to date field value and then

Compare with Self value .

 public class GreaterDateAttribute : ValidationAttribute

{

 

  public string EarlierDateField { get; set; }

 

        protected override ValidationResult IsValid(object value, ValidationContext validationContext)

        {

            DateTime? date = value != null ? (DateTime?)value : null;

            var earlierDateValue = validationContext.ObjectType.GetProperty(EarlierDateField)

                .GetValue(validationContext.ObjectInstance, null);

            DateTime? earlierDate = earlierDateValue != null ? (DateTime?)earlierDateValue : null;

 

            if (date.HasValue && earlierDate.HasValue && date < earlierDate)

            {

                return new ValidationResult(ErrorMessage);

            }

 

            return ValidationResult.Success;

        }

}