ASP' NET

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ASP. NET
Lecture-2
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Agenda

• Introduction to VS.NET
• VB.NET Lang. Basics
• Variables
• Data types
• Identifiers, keywords, literals
• Dimensioning Variables
• Operator
• Expression
• Statements

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Quick Recap

• Web basics
• Internet
• Intranet Extranet
• World Wide Web
• Hypertext
• Resource Identifier
• Client Server
• Markup Language
• HTML
• Client Server Arch.
• Web Browser Web Server

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Start Page

• The Start Page is a tabbed HTML page with three
  main navigation options
• Projects
• Online Resources
• Online Community
• MSDN Headlines
• Search Online
• Downloads
• XML Web services
• My Profile
• This page enables you to set up the general
  settings for your IDE

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Types of Projects
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Creating Visual Basic. NET Projects

• Windows Application
• Standard Windows -based applications.
• Class Library
• Class libraries that provide similar
  functionality to Microsoft ActiveX dynamic-link
  libraries (DLLs) by creating classes accessible
  to other applications.
• Windows Control Library
• User-defined Windows control projects, which are
  similar to ActiveX Control projects in previous
  versions of Visual Basic.
• ASP .NET Web Application
• Web applications that will run from an Internet
  Information Services (IIS) server and can include
  Web pages and XML Web services.

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Creating Visual Basic. NET Projects

• Web Service
• Web applications that provide XML Web Services to
  client applications.
• Web Control Library
• User-defined Web controls that can be reused on
  Web pages in the same way that Windows controls
  can be reused in Windows applications.
• Console Application
• Console applications that will run from a command
  line.
• Windows Service
• Windows services that will run continuously
  regardless of whether a user is logged on or not.
  Previous versions of Visual Basic require you to
  use third-party products or low-level application
  programming interface (API) calls to create these
  types of applications.

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Analyzing Project Structures

• Solution files (.sln, .suo)
• The .sln extension is used for solution files
  that link one or more projects together, and are
  also used for storing certain global information.
• Project files (.vbproj)
• The project file is an Extensible Markup Language
  (XML) document that contains references to all
  project items, such as forms and classes, as w
  ell as project references and compilation
  options.
• Local project items (.vb)
• It may contains classes, forms, modules, and user
  controls

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Solution Explorer

• Displays Project Hierarchy
• Project references
• Forms, classes, modules
• Folders with subitems
• Show All Files Mode
• Manipulating Projects
• Drag-and-drop editing
• Context menus

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Server Explorer

• Managing Data Connections
• Viewing and Managing Servers
• Using Drag-n-Drop Techniques

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Toolbox
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Property Window
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Managing Code Windows and Designers

• Vertical Tab Group

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Managing Code Windows and Designers

• Horizontal Tab Group

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Variable

• A variable can be defined as an entity that has
  the following six properties
• Name
• Address
• Type
• Value
• Scope
• Lifetime

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Data Types
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VB.NET Lang Fundamentals

• Identifiers
• Identifiers are names given to types
  (enumerations, structures, classes, standard
  modules, interfaces, and delegates), type members
  (methods, constructors, events, constants,
  fields, and properties), and variables.
• Identifiers must begin with either an alphabetic
  or underscore character ( _ ), may be of any
  length, and after the first character must
  consist of only alphanumeric and underscore
  characters.
• Keywords
• Keywords are words with special meaning in a
  programming language. In Visual Basic .NET,
  keywords are reserved that is, they cannot be
  used as tokens for such purposes as naming
  variables and subroutines. E.g. (Binary, Boolean,
  ByRef, Byte, ByVal, Auto, integer, Float, else,
  exit )

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VB.NET Lang Fundamentals

• Literals
• A literal is a textual "decorator" that
  represents a particular value type and it forces
  the compiler to treat the object as that
  particular type.
• Literals are representations of values within the
  text of a program.
• For example, in the following line of code, 10
  is a literal, but x and y are not
• x y 10
• Numeric Literals ( Integer I, Single F,
  Double R, and Decimal D, Long L )
• String Literals
• Character Literals followed by char c
• Dim MyChar As Char
• MyChar "A"c
• Date Literals
• Boolean Literals

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Dimensioning Variables

• Two ways
• Dim x as Integer
• Dim x as Integer 7 initialized also here
• Points to note
• You can do it only once per procedure
• Variables have a scope
• Access to variables can be defined Public,
  Private, etc

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Operators

• Operators are symbols (characters or keywords)
  that specify operations to be performed on one or
  two operands (or arguments). Operators that take
  one operand are called unary operators. Operators
  that take two operands are called binary
  operators.
• Type of Operators
• Unary Operators
• Arithmetic Operators
• Relational Operators
• String-Concatenation Operators
• Logical Operators

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Unary Operator

• - (unary minus)
• The unary minus operator takes any numeric
  operand. The value of the operation is the
  negative of the value of the operand. In other
  words, the result is calculated by subtracting
  the operand from zero.
• Not (logical negation)
• The logical negation operator takes a Boolean
  operand. The result is the logical negation of
  the operand.

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Arithmetic Operators

• The arithmetic operators perform the standard
  arithmetic operations on numeric values.
• (multiplication)
• / (regular division)
• The regular division operator is defined for all
  numeric operands. The result is the value of the
  first operand divided by the second operand.
• \ (integer division)
• The integer division operator is defined for
  integer operands (Byte, Short, Integer, and
  Long). The result is the value of the first
  operand divided by the second operand, then
  rounded to the integer nearest to zero.
• Mod (modulo)
• The modulo operator is defined for integer
  operands (Byte, Short, Integer, and Long). The
  result is the remainder after the integer
  division of the operands.

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Arithmetic Operators

• (exponentiation)
• The result is the value of the first operand
  raised to the power of the second operand.
• (addition)
• The addition operator is defined for all
  numeric operands and operands of an enumerated
  type. The result is the sum of the operands.
• - (subtraction)
• The result is the value of the first operand
  minus the second operand.

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Relational Operators

• The relational operators all perform some
  comparison between two operands and return a
  Boolean value indicating whether the operands
  satisfy the comparison.
• (equality)
• ltgt (inequality)
• lt (less than)
• gt (greater than)
• lt (less than or equal to)
• gt (greater than or equal to)
• Like
• TypeOf...Is
• Is

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String Concatenation Operator

• The (ampersand) and (plus) characters signify
  string concatenation. String concatenation is
  defined for operands of type String only. The
  result is a string that consists of the
  characters from the first operand followed by the
  characters from the second operand.
• e.g.
• Dim a as string This is first string
• Dim b as string This is second string
• Dim c as string a b
• Dim d as string a b

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Logical Operators

• Logical operators are operators that require
  Boolean operands. They are
• And
• The result is True if and only if both of the
  operands are True otherwise, the result is
  False.
• Or
• The result is True if either or both of the
  operands is True otherwise, the result is False.
• Xor
• The result is True if one and only one of the
  operands is True otherwise, the result is False.
• Not
• This is a unary operator. The result is True if
  the operand is False False if the operand is
  True.

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Expression

• e.g.
• 5 6
• x y
• BITS Pilani
• x gt y equates to boolean T or F
• day OR night
• objA is Nothing

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Statements

• Are made up of
• Keywords (like Dim)
• Operators
• Variables
• Constants
• Expressions
• Each statement is a command
• Each statement can be on a new line or combined
  together with
• Statements can span multiple lines using _At
  the end
• Your program a lot of statements that do
  interesting things

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Statements

• Types of statements
• Declaration
• Dim x 10
• Assignment
• variable, field, or property expression
• x y 3 6
• Lblcolor.forcolorsystem.drawing.color.red
• Executable
• If Then Else
• Function calls

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Data Type Conversion
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Data Type Conversion

• CBool Convert to Bool data type.
• CByte Convert to Byte data type.
• CChar Convert to Char data type.
• CDate Convert to Date data type.
• CDbl Convert to Double data type.
• CDec Convert to Decimal data type.
• CInt Convert to Int data type.
• CLng Convert to Long data type.
• CObj Convert to Object type.
• CShort Convert to Short data type.
• CSng Convert to Single data type.
• CStr Convert to String type.

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Data Type Conversion

• Ctype(expression, typename )
• e.g.
• 1. Dim a as integer
• Dim var_sng As Single 2.234
• a CInt(var_sng)
• a CType(var_sng, Integer)
• 2. Dim b As Short
• b CShort(a)
• 3. Dim str As String
• str CStr(b)

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Questions???