|
Comentarios
|
|
VB.NET
‘Single line only
Rem
Single
line only
|
C#
// Single line
/* Multiple
line */
/// XML comments on single line
/** XML comments on multiple lines */
|
|
Esctructura del programa
|
|
VB.NET
Imports
System
Namespace
MyNameSpace
Class
HelloWorld
‘Entry
point which delegates to C-style main Private Function
Public
Overloads
Shared
Sub
Main()
Main(System.Environment.GetCommandLineArgs())
End
Sub
Overloads
Shared
Sub
Main(args()
As
String)
System.Console.WriteLine(«Hello
World»)
End
Sub
‘Main
End
Class
‘HelloWorld End Namespace ‘MyNameSpace
|
C#
using
System
Namespace MyNameSpace
{
class
HelloWorld
{
static
void
Main(string[]
args)
{
System.Console.WriteLine(«Hello
World»)
}
}
}
|
|
Tipos de datos
|
|
VB.NET
‘Value Types
Boolean
Byte
Char
(example:
«A»)
Short,
Integer,
Long
Single,
Double
Decimal
Date
‘Reference Types
Object
String
Dim
x
As
Integer
System.Console.WriteLine(x.GetType())
System.Console.WriteLine(TypeName(x))
‘Type conversion
Dim
d
As
Single
=
3.5
Dim
i
As
Integer
=
CType
(d,
Integer)
i
=
CInt
(d)
i
=
Int(d)
|
C#
//Value Types
bool
byte,
sbyte
char
(example: ‘A’)
short,
ushort,
int,
uint,
long,
ulong
float,
double
decimal
DateTime
//Reference Types
object
string
int
x;
Console.WriteLine(x.GetType())
Console.WriteLine(typeof(int))
//Type conversion
float
d
=
3.5;
int
i
=
(int)
d
|
|
Constantes
|
|
VB.NET
Const
MAX_AUTHORS
As
Integer
=
25
ReadOnly
MIN_RANK
As
Single
=
5.00
|
C#
const
int
MAX_AUTHORS
=
25;
readonly
float
MIN_RANKING
=
5.00;
|
|
Enumeraciones
|
|
VB.NET
Enum
Action
Start
‘Stop
is a reserved word
[Stop]
Rewind
Forward
End
Enum
Enum
Status
Flunk
=
50
Pass
=
70
Excel
=
90
End
Enum
Dim
a
As
Action
=
Action.Stop
If
a <> Action.Start
Then
_
‘Prints «Stop is 1»
System.Console.WriteLine(a.ToString &
» is «
& a)
‘Prints 70
System.Console.WriteLine(Status.Pass)
‘Prints
Pass
System.Console.WriteLine(Status.Pass.ToString())
Enum
Weekdays
Saturday
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
End
Enum
‘Weekdays
|
C#
enum
Action {Start, Stop, Rewind, Forward};
enum
Status {Flunk
=
50, Pass
=
70, Excel
=
90};
Action a
=
Action.Stop;
if
(a !=
Action.Start)
//Prints «Stop is 1»
System.Console.WriteLine(a
+
» is «
+
(int)
a);
// Prints 70
System.Console.WriteLine((int)
Status.Pass);
// Prints
Pass
System.Console.WriteLine(Status.Pass);
enum
Weekdays
{
Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday, Friday
}
|
|
Operadores
|
|
VB.NET
‘Comparison
=
< > <= >= <>
‘Arithmetic
+
–
*
/
Mod
\ (integer
division)
^ (raise
to
a power)
‘Assignment
=
+= -= *= /= \=
^=
<<= >>= &=
‘Bitwise
And AndAlso
Or OrElse
Not
<< >>
‘Logical
And
AndAlso
Or OrElse Not
‘String Concatenation
&
|
C#
//Comparison
== < > <= >= !=
//Arithmetic
+
–
*
/
%
(mod)
/
(integer division
if
both operands are ints)
Math.Pow(x, y)
//Assignment
=
+= -= *= /= %= &= |= ^=
<<= >>= ++ —
//Bitwise
& |
^ ~ << >>
//Logical
&& || !
//String Concatenation
+
|
|
Disyunciones
|
|
VB.NET
greeting
=
IIf(age
< 20,
«What’s up?»,
«Hello»)
‘One line doesn’t require «End If», no «Else»
If
language
=
«VB.NET»
Then
langType
=
«verbose»
‘Use: to put two commands on same line
If
x <> 100
And
y < 5
Then
x *= 5 : y *= 2
‘Preferred
If
x <> 100
And
y < 5
Then
x *= 5
y *= 2
End
If
‘or to break up any long single command use _
If
henYouHaveAReally < longLine
And
_
itNeedsToBeBrokenInto2 > Lines Then
_
UseTheUnderscore(charToBreakItUp)
If
x > 5
Then
x *= y
ElseIf
x
=
5
Then
x += y
ElseIf
x < 10
Then
x -= y
Else
x /= y
End
If
‘Must be a primitive data type
Select
Case
color
Case
«black»,
«red»
r += 1
Case
«blue»
b += 1
Case
«green»
g += 1
Case
Else
other += 1
End
Select
|
C#
greeting
=
age < 20 ?
«What’s up?»
:
«Hello»;
if
(x !=
100 && y < 5)
{
// Multiple statements must be enclosed in {}
x *= 5;
y *= 2;
}
if
(x > 5)
x *= y;
else
if
(x == 5)
x += y;
else
if
(x < 10)
x -= y;
else
x /= y;
//Must be integer or string
switch
(color)
{
case
«black»:
case
«red»:
r++;
break;
case
«blue»
break;
case
«green»:
g++;
break;
default:
other++;
break;
}
|
|
Bucles
|
|
VB.NET
‘Pre-test Loops:
While
c < 10
c += 1
End
While
Do
Until
c
=
10
c += 1
Loop
‘Post-test Loop:
Do
While
c < 10
c += 1
Loop
For
c
=
2
To
10
Step
2
System.Console.WriteLine(c)
Next
‘Array or collection looping
Dim
names
As
String()
=
{«Steven»,
«SuOk»,
«Sarah»}
For
Each
s
As
String
In
names
System.Console.WriteLine(s)
Next
|
C#
//Pre-test Loops: while (i < 10)
i++;
for
(i
=
2; i <
=
10; i += 2)
System.Console.WriteLine(i);
//Post-test Loop:
do
i++;
while
(i < 10);
// Array or collection looping
string[]
names
=
{«Steven»,
«SuOk»,
«Sarah»};
foreach
(string
s
in
names)
System.Console.WriteLine(s);
|
|
Matrices
|
|
VB.NET
Dim
nums()
As
Integer
=
{1, 2, 3}
For
i
As
Integer
=
0
To
nums.Length
–
1
Console.WriteLine(nums(i))
Next
‘4 is the index of the last element, so it holds 5 elements
Dim
names(4)
As
String
names(0)
=
«Steven»
‘Throws System.IndexOutOfRangeException
names(5)
=
«Sarah»
‘Resize the array, keeping the existing
‘values (Preserve is optional)
ReDim
Preserve
names(6)
Dim
twoD(rows-1, cols-1)
As
Single
twoD(2, 0)
=
4.5
Dim
jagged()()
As
Integer
=
{ _
New
Integer(4)
{},
New
Integer(1)
{},
New
Integer(2)
{} }
jagged(0)(4)
=
5
|
C#
int[]
nums
=
{1, 2, 3};
for
(int
i
=
0; i < nums.Length; i++)
Console.WriteLine(nums[i]);
// 5 is the size of the array
string[]
names
=
new
string[5];
names[0]
=
«Steven»;
// Throws System.IndexOutOfRangeException
names[5]
=
«Sarah»
// C# can’t dynamically resize an array.
//Just copy into new array.
string[]
names2
=
new
string[7];
// or names.CopyTo(names2, 0);
Array.Copy(names, names2, names.Length);
float[,]
twoD
=
new
float[rows,
cols];
twoD[2,0]
=
4.5;
int[][]
jagged
=
new
int[3][]
{
new
int[5],
new
int[2],
new
int[3]
};
jagged[0][4]
=
5;
|
|
Funciones
|
|
VB.NET
‘Pass by value (in, default), reference
‘(in/out), and reference (out)
Sub
TestFunc(ByVal
x
As
Integer,
ByRef
y
As
Integer,
ByRef
z
As
Integer)
x += 1
y += 1
z
=
5
End
Sub
‘c set to zero by default
Dim
a
=
1, b
=
1, c
As
Integer
TestFunc(a, b, c)
System.Console.WriteLine(«{0}
{1} {2}»,
a, b, c)
‘1 2 5
‘Accept variable number of arguments
Function
Sum(ByVal
ParamArray
nums
As
Integer())
As
Integer
Sum
=
0
For
Each
i
As
Integer
In
nums
Sum += i
Next
End
Function
‘Or use a Return statement like C#
Dim
total
As
Integer
=
Sum(4, 3, 2, 1)
‘returns 10
‘Optional parameters must be listed last
‘and must have a default value
Sub
SayHello(ByVal
name
As
String,
Optional
ByVal
prefix
As
String
=
«»)
System.Console.WriteLine(«Greetings,
«
& prefix
&
» «
& name)
End
Sub
SayHello(«Steven»,
«Dr.»)
SayHello(«SuOk»)
|
C#
// Pass by value (in, default), reference
//(in/out), and reference (out)
void
TestFunc(int
x,
ref
int
y,
out
int
z) {
x++;
y++;
z
=
5;
}
int
a
=
1, b
=
1, c;
// c doesn’t need initializing
TestFunc(a,
ref
b,
out
c);
System.Console.WriteLine(«{0}
{1} {2}»,
a, b, c);
// 1 2 5
// Accept variable number of arguments
int
Sum(params
int[]
nums) {
int
sum
=
0;
foreach
(int
i
in
nums)
sum += i;
return
sum;
}
int
total
=
Sum(4, 3, 2, 1);
// returns 10
/* C# doesn’t support optional arguments/parameters.
Just create two different versions of the same function. */
void
SayHello(string
name,
string
prefix) {
System.Console.WriteLine(«Greetings,
«
+
prefix
+
» «
+
name);
}
void
SayHello(string
name) {
SayHello(name,
«»);
}
|
|
Manjeo de excepciones
|
|
VB.NET
Class
Withfinally
Public
Shared
Sub
Main()
Try
Dim
x
As
Integer
=
5
Dim
y
As
Integer
=
0
Dim
z
As
Integer
=
x
/
y
Console.WriteLine(z)
Catch
e
As
DivideByZeroException
System.Console.WriteLine(«Error
occurred»)
Finally
System.Console.WriteLine(«Thank
you»)
End
Try
End
Sub
‘Main
End
Class
‘Withfinally
|
C#
class
Withfinally
{
public
static
void
Main()
{
try
{
int
x
=
5;
int
y
=
0;
int
z
=
x/y;
Console.WriteLine(z);
}
catch(DivideByZeroException
e)
{
System.Console.WriteLine(«Error
occurred»);
}
finally
{
System.Console.WriteLine(«Thank
you»);
}
}
}
|
|
Namespaces
|
|
VB.NET
Namespace
ASPAlliance.DotNet.Community
…
End
Namespace
‘or
Namespace
ASPAlliance
Namespace
DotNet
Namespace
Community
…
End
Namespace
End
Namespace
End
Namespace
Imports
ASPAlliance.DotNet.Community
|
C#
namespace
ASPAlliance.DotNet.Community {
…
}
// or
namespace
ASPAlliance {
namespace
DotNet {
namespace
Community {
…
}
}
}
using
ASPAlliance.DotNet.Community;
|
|
Clases /
Interfaces
|
|
VB.NET
‘Accessibility keywords
Public
Private
Friend
Protected
Protected
Friend
Shared
‘Inheritance
Class
Articles
Inherits
Authors
…
End
Class
Imports
System
Interface
IArticle
Sub
Show()
End
Interface
‘IArticle
_
Class
IAuthor
Implements
IArticle
Public
Sub
Show()
System.Console.WriteLine(«Show()
method Implemented»)
End
Sub
‘Show
‘Entry point which delegates to C-style main Private Function
Public
Overloads
Shared
Sub
Main()
Main(System.Environment.GetCommandLineArgs())
End
Sub
Overloads
Public
Shared
Sub
Main(args()
As
String)
Dim
author
As
New
IAuthor()
author.Show()
End
Sub
‘Main
End
Class
‘IAuthor
|
C#
//Accessibility keywords
public
private
internal
protected
protected
internal
static
//Inheritance
class
Articles: Authors {
…
}
using
System;
interface
IArticle
{
void
Show();
}
class
IAuthor:IArticle
{
public
void
Show()
{
System.Console.WriteLine(«Show()
method Implemented»);
}
public
static
void
Main(string[]
args)
{
IAuthor author
=
new
IAuthor();
author.Show();
}
}
|
|
Constructores /
Destructores
|
|
VB.NET
Class
TopAuthor
Private
_topAuthor
As
Integer
Public
Sub
New()
_topAuthor
=
0
End
Sub
Public
Sub
New(ByVal
topAuthor
As
Integer)
Me._topAuthor
=
topAuthor
End
Sub
Protected
Overrides
Sub
Finalize()
‘Desctructor
code to free unmanaged resources
MyBase.Finalize()
End
Sub
End
Class
|
C#
class
TopAuthor {
private
int
_topAuthor;
public
TopAuthor() {
_topAuthor
=
0;
}
public
TopAuthor(int
topAuthor) {
this._topAuthor=
topAuthor
}
~TopAuthor() {
// Destructor code to free unmanaged resources.
// Implicitly creates a Finalize method
}
}
|
|
Objetos
|
|
VB.NET
Dim
author
As
TopAuthor
=
New
TopAuthor
With
author
.Name
=
«Steven»
.AuthorRanking
=
3
End
With
author.Rank(«Scott»)
author.Demote()
‘Calling Shared method
‘or
TopAuthor.Rank()
Dim
author2
As
TopAuthor
=
author
‘Both refer to same object
author2.Name
=
«Joe»
System.Console.WriteLine(author2.Name)
‘Prints Joe
author
=
Nothing
‘Free the object
If
author
Is
Nothing
Then
_
author
=
New
TopAuthor
Dim
obj
As
Object
=
New
TopAuthor
If
TypeOf
obj
Is
TopAuthor
Then
_
System.Console.WriteLine(«Is
a TopAuthor object.»)
|
C#
TopAuthor author
=
new
TopAuthor();
//No «With» construct
author.Name
=
«Steven»;
author.AuthorRanking
=
3;
author.Rank(«Scott»);
TopAuthor.Demote()
//Calling static method
TopAuthor author2
=
author
//Both refer to same object
author2.Name
=
«Joe»;
System.Console.WriteLine(author2.Name)
//Prints Joe
author
=
null
//Free the object
if
(author ==
null)
author
=
new
TopAuthor();
Object obj
=
new
TopAuthor();
if
(obj
is
TopAuthor)
SystConsole.WriteLine(«Is
a TopAuthor object.»);
|
|
Estructuras
|
|
VB.NET
Structure
AuthorRecord
Public
name
As
String
Public
rank
As
Single
Public
Sub
New(ByVal
name
As
String,
ByVal
rank
As
Single)
Me.name
=
name
Me.rank
=
rank
End
Sub
End
Structure
Dim
author
As
AuthorRecord
=
New
AuthorRecord(«Steven»,
8.8)
Dim
author2
As
AuthorRecord
=
author
author2.name
=
«Scott»
System.Console.WriteLine(author.name)
‘Prints Steven
System.Console.WriteLine(author2.name)
‘Prints Scott
|
C#
struct
AuthorRecord {
public
string
name;
public
float
rank;
public
AuthorRecord(string
name,
float
rank) {
this.name
=
name;
this.rank
=
rank;
}
}
AuthorRecord author
=
new
AuthorRecord(«Steven»,
8.8);
AuthorRecord author2
=
author
author.name
=
«Scott»;
SystemConsole.WriteLine(author.name);
//Prints Steven
System.Console.WriteLine(author2.name);
//Prints Scott
|
|
Propiedades
|
|
VB.NET
Private
_size
As
Integer
Public
Property
Size()
As
Integer
Get
Return
_size
End
Get
Set
(ByVal
Value
As
Integer)
If
Value < 0
Then
_size
=
0
Else
_size
=
Value
End
If
End
Set
End
Property
foo.Size += 1
Imports
System
Class
[Date]
Public
Property
Day()
As
Integer
Get
Return
day
End
Get
Set
day
=
value
End
Set
End
Property
Private
day
As
Integer
Public
Property
Month()
As
Integer
Get
Return
month
End
Get
Set
month
=
value
End
Set
End
Property
Private
month
As
Integer
Public
Property
Year()
As
Integer
Get
Return
year
End
Get
Set
year
=
value
End
Set
End
Property
Private
year
As
Integer
Public
Function
IsLeapYear(year
As
Integer)
As
Boolean
Return(If
year
Mod
4
=
0
Then
True
Else
False)
End
Function
‘IsLeapYear
Public
Sub
SetDate(day
As
Integer,
month
As
Integer,
year
As
Integer)
Me.day
=
day
Me.month
=
month
Me.year
=
year
End
Sub
‘SetDate
End
Class
‘[Date]
|
C#
private
int
_size;
public
int
Size {
get {
return
_size;
}
set {
if
(value < 0)
_size
=
0;
else
_size
=
value;
}
}
foo.Size++;
using
System;
class
Date
{
public
int
Day{
get {
return
day;
}
set {
day
=
value;
}
}
int
day;
public
int
Month{
get {
return
month;
}
set {
month
=
value;
}
}
int
month;
public
int
Year{
get {
return
year;
}
set {
year
=
value;
}
}
int
year;
public
bool
IsLeapYear(int
year)
{
return
year%4== 0 ?
true:
false;
}
public
void
SetDate (int
day,
int
month,
int
year)
{
this.day
=
day;
this.month
=
month;
this.year
=
year;
}
}
|
|
Delegados /
Eventos
|
|
VB.NET
Delegate
Sub
MsgArrivedEventHandler(ByVal
message
As
String)
Event
MsgArrivedEvent
As
MsgArrivedEventHandler
‘or to define an event which declares a
‘delegate implicitly
Event
MsgArrivedEvent(ByVal
message
As
String)
AddHandler
MsgArrivedEvent,
AddressOf
My_MsgArrivedCallback
‘Won’t throw an exception if obj is Nothing
RaiseEvent
MsgArrivedEvent(«Test
message»)
RemoveHandler
MsgArrivedEvent,
AddressOf
My_MsgArrivedCallback
Imports
System.Windows.Forms
‘WithEvents can’t be used on local variable
Dim
WithEvents
MyButton
As
Button
MyButton
=
New
Button
Private
Sub
MyButton_Click(ByVal
sender
As
System.Object,
_
ByVal
e
As
System.EventArgs)
Handles
MyButton.Click
MessageBox.Show(Me,
«Button was clicked»,
«Info»,
_
MessageBoxButtons.OK, MessageBoxIcon.Information)
End
Sub
|
C#
delegate
void
MsgArrivedEventHandler(string
message);
event
MsgArrivedEventHandler MsgArrivedEvent;
//Delegates must be used with events in C#
MsgArrivedEvent +=
new
MsgArrivedEventHandler
(My_MsgArrivedEventCallback);
//Throws exception if obj is null
MsgArrivedEvent(«Test
message»);
MsgArrivedEvent -=
new
MsgArrivedEventHandler
(My_MsgArrivedEventCallback);
using
System.Windows.Forms;
Button MyButton
=
new
Button();
MyButton.Click +=
new
System.EventHandler(MyButton_Click);
private
void
MyButton_Click(object
sender, System.EventArgs e) {
MessageBox.Show(this,
«Button was clicked»,
«Info»,
MessageBoxButtons.OK, MessageBoxIcon.Information);
}
|
|
Consola I/O
|
|
VB.NET
‘Special character constants
vbCrLf, vbCr, vbLf, vbNewLine
vbNullString
vbTab
vbBack
vbFormFeed
vbVerticalTab
«»
Chr(65)
‘Returns ‘A’
System.Console.Write(«What’s
your name? «)
Dim
name
As
String
=
System.Console.ReadLine()
System.Console.Write(«How
old are you? «)
Dim
age
As
Integer
=
Val(System.Console.ReadLine())
System.Console.WriteLine(«{0}
is {1} years old.»,
name, age)
‘or
System.Console.WriteLine(name &
» is «
& age &
» years old.»)
Dim
c
As
Integer
c
=
System.Console.Read()
‘Read single char
System.Console.WriteLine(c)
‘Prints 65 if user enters «A»
|
C#
//Escape sequences
\n, \r
\t
\\
\
Convert.ToChar(65)
//Returns ‘A’ – equivalent to Chr(num) in VB
// or
(char)
65
System.Console.Write(«What’s
your name? «);
string
name
=
SYstem.Console.ReadLine();
System.Console.Write(«How
old are you? «);
int
age
=
Convert.ToInt32(System.Console.ReadLine());
System.Console.WriteLine(«{0}
is {1} years old.»,
name, age);
//or
System.Console.WriteLine(name
+
» is «
+
age
+
» years old.»);
int
c
=
System.Console.Read();
//Read single char
System.Console.WriteLine(c);
//Prints 65 if user enters «A»
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Ficheros I/O
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VB.NET
Imports
System.IO
‘Write out to text file
Dim
writer
As
StreamWriter
=
File.CreateText
(«c:\myfile.txt»)
writer.WriteLine(«Out
to file.»)
writer.Close()
‘Read all lines from text file
Dim
reader
As
StreamReader
=
File.OpenText
(«c:\myfile.txt»)
Dim
line
As
String
=
reader.ReadLine()
While
Not
line
Is
Nothing
Console.WriteLine(line)
line
=
reader.ReadLine()
End
While
reader.Close()
‘Write out to binary file
Dim
str
As
String
=
«Text data»
Dim
num
As
Integer
=
123
Dim
binWriter
As
New
BinaryWriter(File.OpenWrite
(«c:\myfile.dat»))
binWriter.Write(str)
binWriter.Write(num)
binWriter.Close()
‘Read from binary file
Dim
binReader
As
New
BinaryReader(File.OpenRead
(«c:\myfile.dat»))
str
=
binReader.ReadString()
num
=
binReader.ReadInt32()
binReader.Close()
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C#
using
System.IO;
//Write out to text file
StreamWriter writer
=
File.CreateText
(«c:\\myfile.txt»);
writer.WriteLine(«Out
to file.»);
writer.Close();
//Read all lines from text file
StreamReader reader
=
File.OpenText
(«c:\\myfile.txt»);
string
line
=
reader.ReadLine();
while
(line !=
null)
{
Console.WriteLine(line);
line
=
reader.ReadLine();
}
reader.Close();
//Write out to binary file
string
str
=
«Text data»;
int
num
=
123;
BinaryWriter binWriter
=
new
BinaryWriter(File.OpenWrite
(«c:\\myfile.dat»));
binWriter.Write(str);
binWriter.Write(num);
binWriter.Close();
//Read from binary file
BinaryReader binReader
=
new
BinaryReader(File.OpenRead
(«c:\\myfile.dat»));
str
=
binReader.ReadString();
num
=
binReader.ReadInt32();
binReader.Close();
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