Cours VB.NET

Private Sub Command1_Click()
Dim i As Long
Dim j As Long
Dim k As Long
For i = 0 To 100
For j = 0 To 1000
Label1.Caption = Str(k * 2 + Sin(4)): Label1.Refresh
k = k + 1
Next
Next
End Sub

Imports System.Math

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _ 
 Handles Button1.Click
Dim i As Integer
Dim j As Integer
Dim k As Integer
For i = 0 To 100
For j = 0 To 1000
Label5.Text = (k * 2 + Sin(4)).ToString : Label5.Refresh()
k = k + 1
Next
Next
End Sub

Private Sub Command1_Click()

Dim i As Integer
Dim A(10000) As String
Dim j As Integer
Dim N As Integer
Dim Temp As String
N = 9999
'remplir le tableau
For i = 9999 To 0 Step -1
    A(i) = Str(9999-i)
Next i
'trier
For i = 0 To N - 1
    For j = 0 To N - i - 1

       If A(j) > A(j + 1) Then
            Temp = A(j): A(j) = A(j + 1): A(j + 1) = Temp
        End If
 Next j
Next i
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _ 
 Handles Button1.Click
Dim i As Integer
Dim A(10000) As String
For i = 9999 To 0 Step -1
A(i) = (9999 - i).ToString
Next i
Array.Sort(A)
Label1.Text = "ok"
End Sub

Dim Debut, Fin As DateTime

Dim Durée As TimeSpan

Debut=Now

...Routine...

Fin=Now

Durée=Fin-Debut

Dim Debut, Fin As int32

Debut=Environment.tickcount()

...Routine...

Fin=Environment.tickcount()
Durée=Fin-Debut

Declare Function QueryPerformanceCounter Lib "Kernel32" (ByRef X As Long) As Short

Declare Function QueryPerformanceFrequency Lib "Kernel32" (ByRef X As Long) As Short

Private Sub ButtonGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonGo.Click

Dim debut As Long

Dim fin As Long

Dim i As Long

Dim a(5) As String

Dim b As String

Dim c As String

Dim d1 As Long

Dim d2 As Long

'**********première routine

QueryPerformanceCounter(debut)

For i = 0 To 10000

b = a(2)

Next

QueryPerformanceCounter(fin)

d1 = fin - debut

Label1.Text = d1.ToString

'**********seconde routine

QueryPerformanceCounter(debut)

c = a(2)

For i = 0 To 10000

b = c

Next

QueryPerformanceCounter(fin)

d2 = fin - debut

Label2.Text = d2.ToString

 

Label5.Text = "Gain 2eme routine:" & 100 - Int(d2 / d1 * 100).ToString

End Sub

Dim Stopwatch As System.Diagnostics.stopWatch = System.Diagnostics.Stopwatch.StartNew()

' Code à mesurer
MsgBox(stopWatch.ElapsedMilliseconds.ToString())

Dim S As System.Diagnostics.stopWatch = System.Diagnostics.Stopwatch.StartNew()

'routine à mesurer

S.Stop()
Dim t1 As Decimal = S.ElapsedTicks
        MsgBox( t1.ToString)

stopwatch.Stop     'arrête le compteur

stopwatch.Start    'fait redémarrer le compteur

stopwatch.Reset()  'remet le compteur à zéro

stopwatch.Restart()  'redémmare le compteur (A partir de VB 2010)
				

Dim PC As New PerformanceCounter()
PC.CategoryName = "Process"
PC.CounterName = "Private Bytes"
PC.InstanceName = "Explorer"
MessageBox.Show(PC.NextValue().ToString())

Array.Sort(A)

For i = 0 To N - 1
    For j = 0 To N - i - 1

        If A(j) > A(j + 1) Then
            Temp = A(j): A(j) = A(j + 1): A(j + 1) = Temp
        End If

    Next j
Next i

I=Array.BinarySearch(Mois, "Février")

Dim a As Integer= P(6)

b=a*3

c=a+2

...

z=a*5

b=P(6)*3

c=P(6)+2

...

z=P(6)*5

Dim Mois() As String ={Janvier,Février,Mars,Avril,Mai,Juin,Juillet}

nomDuMois=Mois(i-1)

Select Case i

    Case 1

        nomDuMois="Janvier"

    Case 2

        nomDuMois="Février"

    ....

End Select.

Dim A  crée un 'Objet' A

Dim A As String

Select Case Variable

Case Valeur1

... Valeur1 revient souvent

Case Valeur2

...

...

Case Valeur25

... Valeur25 survient rarement

End Select

 

if x<3 And y>15 then

if x<3 then

    If y>15 then

..

For i=1 to 100000

    R=i*P+ Log(2)

next i

For i=1 to 100000

    R=i*P+ 0.693147

next i

For i=1 to 100000

    R=i*P+ Myobjet.MyPropriété

next i

Dim valeur As Integer = Myobjet.MyPropriété

For i=1 to 100000

    R=i*P+ valeur

next i

For i=1 to 100000

    R=i*P+ MyTableau (2 ,3 )

next i

Dim valeur As Integer= MyTableau (2 ,3)

For i=1 to 100000

    R=i*P+ valeur

next i

With Form1.TextBox1

    .BackColor= Red

    .Text="BoBo"

    .Visible= True

End With

Form1.TextBox1.BackColor= Red

Form1.TextBox1.Text="BoBo"

Form1.TextBox1.Visible= True

For i=1 to 100000

    R=i*J(1,2)

next i

Dim P as Integer

P=J(1,2)

For i=1 to 100000

    R=i*P

next i

For i=1 to 100000

    P(i)=i

Next i

For i=1 to 100000

    Q(i)=i

Next i

Faire:

For i=1 to 100000

    P(i)=i

    Q(i)=i

Next i

For i=1 to 100    '100 itérations

For j=1 to 10     '100 X 10 itérations

    ...

Next j

Next i

100+(100X10) = 1100 itérations de compteur

 

For j=1 to 10     '10 itérations

For i=1 to 100    '100 X 10 itérations

    ...

Next j

Next i

10+(100X10) = 1010 itérations de compteur

 
 Dim iteration, boucle, i, j As Integer
 
 Private Sub Button1_Click
        For i = 1 To 100    '100 iterations
            iteration = itération + 1
            For j = 1 To 10     '100 X 10 iterations
                iteration = iteration + 1
                boucle = boucle + 1

            Next j

        Next i
        MsgBox(iteration)
        '100+(100X10) = 1100 iterations de compteur

        iteration = 0 : boucle = 0

        For j = 1 To 10     '10 iterations
            iteration = iteration + 1
            For i = 1 To 100    '100 X 10 iterations
                iteration = iteration + 1
                boucle = boucle + 1

            Next i

        Next j
        MsgBox(iteration)
        '10+(10X100) = 1010 iterations de compteur

    End Sub

 For i=1 to 100000

        resultat= Calcul(i,j)

    Next i

     

    Functin Calcul (i As Integer, j As Integer)

        i=i+3

        Return i*j

    End Sub

    C'est plus rapide d'écrire:

    For i=1 to 100000

        i=i+3

        resultat= i*j

    Next i

     

  s &= "mon" & "ami"

   s += "mon" + "ami"

 Dim s As String = "bonjour"
     

    s += "mon" + "ami"

 Dim sb As new System.Text.StringBuilder()

    sb.Append("bonjour")

    sb.Append("mon ami")

    Dim s As String

    s = sb.ToString()

TextBox1.Text = TextBox1.Text + "Bonjour"

TextBox1.Text = TextBox1.Text + ""Monsieur"

Dim T as string

T = "Bonjour"

T &= "Monsieur"

TextBox1.Text = T