Table + array + files Learn programming Visual Basic (VB.net)

Lesson:

Object Persistence


Exercise:

Table + array + files


Objetive:

Expand the January 9th exercise (tables + array) by adding two new methods to dump the data of the array into a binary file and restore the data from the file.


Code:

Imports System
Imports System.IO
Namespace Tables
    Class Table
        Protected width, height As Integer

        Public Sub New(ByVal tableWidth As Integer, ByVal tableHeight As Integer)
            width = tableWidth
            height = tableHeight
        End Sub

        Public Sub ShowData()
            Console.WriteLine("Width: {0}, Height: {1}", width, height)
        End Sub

        Public Sub Save(ByVal name As String)
            Dim outputFile As BinaryWriter = New BinaryWriter(File.Open(name, FileMode.Create))
            outputFile.Write(height)
            outputFile.Write(width)
            outputFile.Close()
        End Sub

        Public Sub Load(ByVal name As String)
            Dim inputFile As BinaryReader = New BinaryReader(File.Open(name, FileMode.Open))
            height = inputFile.ReadInt32()
            width = inputFile.ReadInt32()
            inputFile.Close()
        End Sub
    End Class
End Namespace

Namespace Tables
    Class TestTable
        Private Shared Sub Main(ByVal args As String())
            Dim tableList As Table() = New Table(9) {}
            Dim random As Random = New Random()

            For i As Integer = 0 To tableList.Length - 1 - 1
                tableList(i) = New Table(random.[Next](50, 201), random.[Next](50, 201))
            Next

            tableList(0).Save("1.dat")
            tableList(9) = New Table(0, 0)
            tableList(9).Load("1.dat")

            For i As Integer = 0 To tableList.Length - 1
                tableList(i).ShowData()
            Next

            Console.ReadLine()
        End Sub
    End Class
End Namespace

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