Hi there,

For a school project I need to create a Bingo game based on a 2D Array.
Just like a real Bingo card the numbers need to be unique.

I managed to create a card with random numbers as shown in the code below, but I have no clue how to generate unique random numbers.

Any suggestions?

Code:
Public NotInheritable Class MainPage
    Inherits Page

    Dim BingoArray(7, 7) As Short
    Dim generator As New Random
    Dim size As Integer

    Private Sub generateCardBtn_Click(sender As Object, e As RoutedEventArgs) Handles generateCardBtn.Click
        Dim i As Integer 'amount rows (first dimension)
        Dim j As Integer 'amount collumns (2nd dimension)
        Dim k As Integer 'rows & collumns size
        Dim minVal As Integer
        Dim maxVal As Integer
        Dim randNum As Integer

        If twentyfiveRdBtn.IsChecked Then
            size = 25
            k = Math.Sqrt(size)

            ReDim BingoArray(k, k) 'Redim card size

            For i = 0 To BingoArray.GetUpperBound(0) - 1 'preserve one row in card / first dimension
                For j = 0 To BingoArray.GetUpperBound(1) - 1 'preserve one row in card / second dimension
                    minVal = (i * 10) + 10
                    maxVal = (i * 10) + 20 - 1

                    randNum = generator.Next(minVal, maxVal)

                    BingoArray(i, j) = randNum

                    bingoCardTxtBox.Text += BingoArray(i, j) & "  "
                Next
                    bingoCardTxtBox.Text += vbNewLine
                Next
        End If
    End Sub
End Class