Comment faire pour utiliser des accès de fichier binaire avec Visual Basic

Étapes pour créer cet exemple :

1. Démarrez un nouveau projet EXE Standard Visual Basic. Form1 est créé par défaut.
2. Dans le menu projet, sélectionnez Ajouter un module pour ajouter un module standard au projet. Module1 est créé par défaut.
3. Dans le menu projet, sélectionnez Propriétés Projet1 pour afficher la boîte de dialogue Propriétés du projet. Sélectionnez l'onglet Général et modifiez l'objet de démarrage Sub Main.
4. Ajoutez le code suivant à la section déclarations générales de Module1 :

   Option Explicit
   ' define structure of a variable-length record
   Type Person_VariableLength
       ID               As Integer
       MonthlySalary    As Currency
       LastReviewDate   As Long
       FirstName        As String
       LastName         As String
       Title            As String
       ReviewComments   As String
   End Type
   
   ' define structure of a fixed-length record
   Type Person_FixedLength
       ID               As Integer
       MonthlySalary    As Currency
       LastReviewDate   As Long
       FirstName        As String * 15
       LastName         As String * 15
       Title            As String * 15
       ReviewComments   As String * 150
   End Type
   
   ' variables for sample data
   Private binSampleOne As Person_VariableLength
   Private binSampleTwo As Person_VariableLength
   Private randomSampleOne As Person_FixedLength
   Private randomSampleTwo As Person_FixedLength
   
   ' record number for use with random (fixed-length) file
   Private intRecNum As Integer
   
   Public Sub main()
       buildSampleRecords
       demonstrateBinary
       demonstrateRandom
   End Sub
   
   Private Function demonstrateBinary()
       ' open the file and write the records
       Open "c:\BINsample" For Binary As #1
       Put #1, , binSampleOne
       Put #1, , binSampleTwo
       Close #1
       
       ' open the file and read the records
       Open "c:\binSample" For Binary As #1
       Dim udtPerson As Person_VariableLength
       Do While Not EOF(1)
           Get #1, , udtPerson
           ' display selected values
           With udtPerson
               Debug.Print .FirstName
               Debug.Print .LastName
               Debug.Print .ReviewComments
           End With
       Loop
       Close #1
   End Function
   
   Private Function demonstrateRandom()
       ' open the file and write the records
       Dim recSize As Person_FixedLength
       Open "c:\Randomsample" For Random As #1 Len = Len(recSize)
       Put #1, 1, randomSampleOne
       Put #1, 2, randomSampleTwo
       Close #1
       
       'open the file and read the records
       Dim udtPerson As Person_FixedLength
       Open "c:\randomsample" For Random As #1 Len = Len(udtPerson)
       ' demonstrate random access capability by reading file backwards
       For intRecNum = 2 To 1 Step -1
           Get #1, intRecNum, udtPerson
           ' display selected values
           With udtPerson
               Debug.Print .FirstName
               Debug.Print .LastName
               Debug.Print .ReviewComments
           End With
       Next intRecNum
       Close #1
   End Function
   
   Private Sub buildSampleRecords()
   ' routine to build sample records
   ' note that populating the data of the User Defined Type is the
   ' same regardless of fixed or variable length members
      With binSampleOne
           .ID = 1
           .MonthlySalary = 50000
           .LastReviewDate = #2/2/2000#
           .FirstName = "Wilma"
           .LastName = "Flintstone"
           .Title = "Movie Star"
           .ReviewComments = "Contract renewed for sequel"
       End With
       With binSampleTwo
           .ID = 2
           .MonthlySalary = 50000
           .LastReviewDate = #2/2/2000#
           .FirstName = "Fred"
           .LastName = "Flintstone"
           .Title = "Movie Star"
           .ReviewComments = "Replace with Clint Eastwood for sequel"
       End With
       With randomSampleOne
           .ID = 1
           .MonthlySalary = 50000
           .LastReviewDate = #2/2/2000#
           .FirstName = "Wilma"
           .LastName = "Flintstone"
           .Title = "Movie Star"
           .ReviewComments = "Contract renewed for sequel"
       End With
       With randomSampleTwo
           .ID = 2
           .MonthlySalary = 50000
           .LastReviewDate = #2/2/2000#
           .FirstName = "Fred"
           .LastName = "Flintstone"
           .Title = "Movie Star"
           .ReviewComments = "Replace with Clint Eastwood for sequel"
       End With
   End Sub
   					

5. Assurez-vous que la fenêtre exécution est affichée. S'il n'est pas le cas, vous devez sélectionner à partir du menu affichage.
6. Exécutez le projet et notez que les résultats sont affichés dans la fenêtre exécution.

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