Cours VB.NET

Dim P As New Point(45, 78)

P= Nothing

Dim P As New MaClasse

Dim P As Maclasse    'déclaration

P As New Maclasse    'instanciation

Module Mon module

    Public P As MaClasse

 

Sub MaRoutine

    P As New MaClasse

End Sub

End Module 

Dim B As New Button

B.Name ="toto"

Dim B As New Button

Dim I As Class1

	I = New Class1

Dim I As New Class1  

Class Class1
   Public Value As Integer = 0
End Class

Dim C1 As New Class1()
Dim C2 As Class1 =C1    'on crée C2, on affecte C1 à C2
C2.Value = 123          'on modifie C2
 

=> C1.Value=123  C2.Value=123    

Class Class1
   Public Value As Integer = 0
End Class

Dim C1 As New Class1()
C1.Value= 555
Dim C2 As Class1 =C1.Clone    'on crée C2, on clone 
C2.Value = 123          'on modifie C2
 
'C1.Value=555  C2.Value=123    

Dim O As Object

Dim Q As Object  

If O Is Q then..

Obj1.Equals(Obj2))  'Retourne True si Obj1 et Obj2 ont le même pointeur.

Nom
Laboratoire
Nombre de médicament.
.. 

Medicament.Nom
Medicament.Laboratoire
Medicament.NbdeMedicament

Dim MonMedicament As New Medicament

MonMedicament.Nom
MonMedicament.Laboratoire
MonMedicament.NbdeMedicament

Dim MonMedicament As New Medicament()

MonMedicament.Nom= "Aspirine": MonMedicament.Laboratoire="RP"

LeNom=MonMedicament.Nom  : Nb= MonMedicament.NombreMedicament

Public Class Medicament
...
End Class

Private _mNom As String 

Public Laboratoire As String

Public ReadOnly NombreMedicament=2000

Public Class Medicament
    Public Laboratoire As String    'variable d'instance
    Public Shared Societe as String 'variable de classe Shared
End Class
 
Dim M1 As New Medicament
Dim M2 As New Medicament
 
M1.Laboratoire= "MVV"
M2.Laboratoire= "VVT" 

M1.Societe="ooo"

Dim MonMedicament As New Medicament()
MonMedicament.Nom= "Amoxicilline" : Nom est une Property.

Property Nom() 
Get  
End Get
Set (By Val Value)
End Set
End Property

Public Class Medicament
 
'Variable privée (Attribut) servant à stocké en interne le nom.
Private _mNom As String
 
'Propriété Nom
Public Property Nom() as String
Get  
    Return _mNom
End Get
Set(By Val Value)
    _mNom=value
End Set
End Property
 
End Class

Public ReadOnly Property InitialeNom() As String
Get
 Return Left(_mNom,1) 
End Get
End Property

Public Class employee
    Private salaryValue As Double
    Protected Property salary() As Double
        Get
            Return salaryValue
        End Get
        Private Set(ByVal value As Double)
            salaryValue = value
        End Set
    End Property
End Class

'Code complet
Private _MaProperty As String = "Empty"
Property MaProperty As String
    Get
        Return _MaProperty
    End Get
    Set(ByVal value As String)
        _MaProperty = value
    End Set
End Property

'Peut être remplacé par:
Property MaProperty As String = "Empty"

Property ID() As Integer = -2
Property ManList() As New List(Of Man)

Public Class Personne
    Property Nom As String
    Property Prenom As String
End Class
.....


Dim FirstPersonne As New Personne
FirstPersonne.Nom= "Las"
FirstPersonne.Prenom= "Philippe"

'En VB 2010 on peut aussi écrire:
Dim FirstPersonne As New Personne With {.Nom = "Las", .Prenom = "Philippe"}

Public Sub Dessine() As Double
' Code
End Sub

 
Public Class Medicament
'Variables ou Attributs
Private _nom As String
 
'Accesseurs
Public Sub GetNom() As String
    Return _nom
End Sub
 
'modificateurs
Public Sub SetNom (ByVal N As String)
    Me._nom= N
EndSub
End Class
 

Sub New()
End sub

Sub New(ByVal LeNom As String)
    _mNom=LeNom
End sub

Classe Homme
Private _Nom As String
Private _Prenom As String
Public Sub initialise(ByVal N As String, ByVal P As String)
    Me._nom = N
    Me._prenom = P
End Sub
End Class

dim p as New Homme()
p._prenom="Philippe" est refusée
On écrira donc :
dim p as New Homme
p.initialise("Monnom", "Philippe")

Protected Overrides Sub Finalize ()
End Sub

Implements IDisposable

 
Public Sub Dispose() Implements System.IDisposable.Dispose
' Code libérant les ressources (Base de données, connexion, Objets systèmes..)...
End sub

M.Dispose()
M=Nothing
 

Class Figure
Sub New()
    Bla Bla
End Sub
 
Sub New( ByVal X As Integer, ByVal Y As Integer)
     Blabla
End Sub. 
End Class
 On peut donc instancier la classe correspondante de 2 manières:
Dim A As New Figure    'Constructeur par défaut
ou
Dim A As New Figure(100,150)
 

Class Figure
Public Overloads Property Calcul()
    Bla Bla
End Sub
 
Public Overloads Property Calcul( ByVal X As Integer, ByVal Y As Integer)
     Blabla
End Sub. 
End Class

Public Class Class1
Private _mTexte As String
 
' Déclare un évènement
Public Event TextChange(ByVal UserName As String)
 
Public Property Texte()
Get
    Return _mTexte
End Get
Set(ByVal Value)
If Value <> _mTexte Then
  RaiseEvent TextChange("hello")'<= déclenchement de l'évènement par RaiseEvent
End If
_mTexte = Value
End Set
End Property
 
End Class

Public Property MaValeur() As Integer
    Get
    ..
    End Get
    Set (ByVal Value As Integer)
        If Value>=0 Then
            _mValeur= Value
        Else
            Throw New Exception ("La valeur " & Value.ToString & " est invalide")
        End If
    End Set
End Property

Public Class MaClasse
    'implementation...
End Class

Partial Public Class MaClasse
    'implementation...
End Class

Partial Private Sub MyMethode()
End Sub

Partial Class Product 
Private _Quantity As Integer 
Property Quantity() As Integer 
...
End Property
 
Partial Private Sub QuantityChanged() 
End Sub 
 
End Class

Partial Class Product</b>				

Private Sub QuantityChanged()

     MsgBox("Quantity was changed to " & Me.Quantity) 

End Sub 

End Class

 

Class baseClass
    'Classe de base (parente)
    Public Overridable Sub testMethod()
        MsgBox("Base class string (parente)")
    End Sub
    Public Sub useMe()
        ' Utilise la classe en cours même si 
        ' la méthode a été overridé.
        Me.testMethod()
    End Sub
    Public Sub useMyClass()
        ' Utilise la classe en cours si elle a été overidé 
        ' Utilise la classe parent si  pas d' override.
        MyClass.testMethod()
    End Sub

    Public Sub useMyBase()
        ' Utilise la méthode de la classe parente.
        MyBase.testMethod()
    End Sub
End Class

Class derivedClass : Inherits baseClass
    'Classe dérivée debaseClass
    Public Overrides Sub testMethod()
        MsgBox("Derived class string (enfant)")
    End Sub
End Class

Class testClasses
    'Classe pour tester
    Sub startHere()
        Dim testObj As derivedClass = New derivedClass()
        ' Usage de Me
        ' Ce qui suit affiche  "Derived class string (enfant)" toujours.
        testObj.useMe()
        
        ' Usage de MyClasse
        ' Ce qui suit affiche  "Base class string(parente)" car testMethod overidé.
        testObj.useMyClass()
        
        ' Usage de MyBase
        ' Ce qui suit affiche  "Base class string(parente)" toujours .
        testObj.useMyBase()
    End Sub
End Class

Me.Icon = My.Resources.MyIcon

My.Computer.Audio.Play(My.Resources.Form1Greeting, AudioPlayMode.Background)

Class MyClasse
Default Property MonItem As String
..
End Property
End Class
 

Dim MyCollection As New MyClasse

MyCollection.MonItem (index)

MyCollection(index)    'MonItem est omis

Class Test
   Private _x As Integer
   Private Shared _y As Integer
   
   Sub F()
      _x = 1 ' Ok, c'est équivalent à Me._x = 1.
      _y = 1 ' Ok, c'est équivalent à Test._y = 1.
   End Sub
   
   Shared Sub G()
      _x = 1 ' Erreur, on ne peut accéder à Me._x.
      _y = 1 ' Ok, c'est équivalant à Test._y = 1.
   End Sub
End Class
   
   Shared Sub Main()
      Dim t As New Test()
      t._x = 1 ' Ok.
      t._y = 1 ' Ok.
      Test._x = 1 ' Erreur, on accède à x seulement par une instance.
      Test._y = 1 ' Ok  on peut accéder à y avec le nom de la classe car y est shared.
   End Sub

Class MyClasse

Private Shared Nb as Integer=0

Sub New()
    Nb+=1
End sub
 

Public ReadOnly Property NbInstance()
    Get
        NbInstance=Nb
    End Get
End Property 
 
End Class
 

Private m_ID As System.Guid
Sub New()
    m_ID = System.Guid.NewGuid
End Sub

'0f8fad5b-d9cb-469f-a165-70867728950e  

Private Sub New()

Shared Function getInstance() As sing

Shared instance As sing

Public Class sing
'Déclaration de l'instance Singleton
Shared instance As sing
 
Private Sub New()'Pas oublier de mettre Private 
    MyBase.New()
End Sub
Shared Function getInstance() As sing 'Voici la méthode de classe
 
If IsNothing(instance) Then 'Si le singleton n'est pas créé, alors faut le créé
    instance = New sing
End If
Return instance
End Function
...
...
End Class

Dim t As sing =  sing.getInstance

    Shared Function getInstance() As sing
         
        If IsNothing(instance) Then 
            SyncLock GetType(sing) 
                 If IsNothing(instance) Then 
                    instance = New sing 
                end if 
            End SyncLock 
        End If 
        Return instance 
    End Function 

Public Classe height
    ...
    Public Shared Operator +(ByVal h1 As height, ByVal h2 As height)As height
        Return New height(h1.feet + h2.feet, h1.inches + h2.inches)
    End Operator
End Structure

Public Shared Operator IsTrue(ByVal e As Personne) As Boolean

If e Is Nothing Then

    Return False

Else

    Return e.Present

End If

End Operator

Public Shared Operator IsFalse(ByVal e As Personne) As Boolean

    Return Not e

End Operator

If e then.. 

Public Shared Widening Operator CType(ByVal e As Personne) As String

Return e.Nom + " " + e.Prenom

End Operator

 

Public Shared Widening Operator CType(ByVal  e As Personne) As Date

If e Is Nothing Then

    Return Nothing

Else

    Return e.DateDeNaissance

End If

End Operator

 

Public Shared Widening Operator CType(ByVal  e As Personne) As Boolean

    If e Is Nothing Then Return False Else Return e.Present

End Operator

Public Class Temperature
    Private temp As Decimal

    Public Sub New(ByVal temperature As Decimal)
        Me.temp = temperature
    End Sub

    Public Overrides Function ToString() As String
        Return Me.temp.ToString("N3") + "°C"  'format nombre avec 3 chiffres après la virgule = '°C'
    End Function
End Class

        Dim currentTemperature As New Temperature(23.6D)
        Console.WriteLine("The current temperature is {0}.", currentTemperature)
        'Affiche The current temperature is 23,600°C.

Public Class Class1
End Class

NameSpace Outils
End
 

NameSpace Outils
NameSpace Marteau
....
End
End
 

NameSpace Outils
Classe Marteau
....
End Class
End

Imports Outils.Marteau
 

Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs)
 
MyBase.OnMouseDown(e) 'Appel à la méthode de la classe de base
If e.X < Me.Width / 2 Then 
    MessageBox.Show("Click sur partie gauche") 
Else
    MessageBox.Show("Click sur partie droite") 
End if
End Sub
 

Public Class UserControl1
Inherits System.Windows.Forms.UserControl
End Class
 

Private Button1_Click
End Sub

Private Sub UserControl1_Load(..
End Sub

Public Property LeTexte() As String
    Get
        LeTexte=TextBox1.Text
    End Get
    Set (ByVal Value As String)
        If Value <> "toto" Then
            TextBox1.Text= Value
        End if
    End Set
End Property

UserControl1.LeTexte="lulu"    'lulu apparaît dans le textbox
 
UserControl1.LeTexte="toto"    'rien n' apparaît dans le textbox: : j'ai bien modifié le comportement du textbox 
'et c'est transparent pour l'utilisateur.