Transcript Document

VB and C# Programming Basics
Overview
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Basic operations
String processing
Date processing
Control structures
Functions and subroutines
Additional Documentation
• For extensive documentation in Microsoft .NET
Development using VB or C#:
– http://msdn.microsoft.com/en-us/library/dd642420.aspx
The System Namespace
• Contains fundamental classes, including
String and DateTime
• System Namespace Documentation
– http://msdn.microsoft.com/enus/library/system.aspx
String Processing
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Concatenation
String length
Substrings
Changing case
Replacing text
• Hyperlink to String class documentation
String concatenation
Note: C# is case sensitive.
Length property begins with
upper-case “L”
Returning string lengths
Substring method
of String class.
1st argument = start
position
2nd (optional)
argument = length
of substring
Indexof method
of String class
Returns the 0-based
index position of the
substring in the
searched string.
Syntax:
searchedString.Indexof
(stringToFind)
searchedString.Indexof
(stringToFind, startPos)
Changing case
Replacing
text in a
string
The DateTime Class
• Provides many useful properties and
methods related to dates and times
• Hyperlink to DateTime documentation
Date
Manipulation
Lots of
methods and
properties
for the
DateTime
class!
Additional Notes
• In C#, use DateTime.Parse static method to
convert a string to date. Not necessary in VB.
– Try changing from DateTime.Now to a string
representing a date and time
• To make the view source more readable, you
can insert line breaks in your output string:
– “\n” for C#
– ControlChars.CrLf for VB
Control Structures
• Selection
– if – else
– select case ----- switch
• Looping
– for loops
– while and do while loops
Syntax for if
statements in C#
is identical to
what you know
from Java
VB Select-Case
like before
Note: C# switch
statement allows case to
include
strings…different from
Java, which requires
integral values
for loop
syntax
similar to
what you
know of
Java
Note: unlike Java, C#
includes a foreach
keyword in the core
language.
while in C# is similar to what
you know already in Java
Functions and Subroutines
• Signatures – return type, name, parameter
list
• Calling functions and subroutines
• Making use of return values
Note: with VB .NET,
explicit type
declarations not
necessary
Note the use of
ToString
method…converts
numeric values to
strings for text
output.
Note that the int data type (and other primitive data types)
provides the possibility of converting data to string via
ToString(). In this sense it operates like a Java wrapper class.
Array Processing
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Array declaration, instantiation, initialization
Single-dimensional arrays
Multi-dimensional arrays
Jagged arrays
Single Dimension Arrays C#
Declaration in C# is strict,
brackets must follow data
type: int[] array1;
NOT int array1[];
Looping through arrays
can be done using Length
property or via for each
loop
Single Dimension Arrays VB
Multi Dimension Arrays C#
Multi-dimension array declaration and
use in C# is unlike Java. With Java you
are always declaring jagged arrays, but
C# has a feature for multi-dimension
arrays
Multi Dimension Arrays VB
Length vs. GetLength():
Length returns full array size
GetLength(x) returns nbr
elements in row x
Jagged Arrays C#
Jagged arrays are familiar to
Java programmers
Jagged Arrays VB
Web Server Controls
for Assignment #1
• TextBox
– Two Useful Properties:
• Text – contains the string for user input
• Columns – specifies visible number of characters
• Button
– Event processing via ONCLICK attribute in
ASP:Button tag
• Label
– Static text display
Note initialization of
server control properties
in the Page_Load
procedure
Association of click event
with event-handling
routine
Resulting HTML code
Resulting browser render
The web.config file
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Useful for deployment and configuration
Primarily for web administration
Can also be used for creating global application variables
XML file
If used, should be placed in application’s root folder
For debugging purposes, you should do the following……
In your web.config file, change the tag that says:
– <customErrors mode="RemoteOnly" />
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– <customErrors mode="Off"/>
• This will enable compile errors in your code to be identified when
attempting to view the page in a browser