Memory Game click events and random number generator - arrays

Question

So I am building a Memory Game. This is a 2 part question. I have 16 boxes being used and need to have the numbers 1-8 twice. I have set up each box as a structure and have a random number generator randomly picking a number for a box and then randomly placing a number 1 - 8 into it. Problem I am coming across is this. I am getting repeat numbers for my boxes and more than 2 times for a digit that will be placed in that box, sometimes no sequential number being used all together. How can I make sure all 16 boxes are being created with out having to make code for 16 different instances. Also need to make sure each single digit number between 1-8 is being used and only used twice?
Second part of my question is I am having an issue with making a click event when a user chooses a box. Right now I can't figure out how to associate which box the user clicks on. I don't want to write code for 16 different boxes, link an array to each box and then populate each box that array's guess number. Is there a way I can simplify that code down to something short?
I have included all the code so far.
Option Strict On
Option Explicit On
Option Infer Off
Public Class Form1
Structure MemoryBox
Public intBox As Integer
Public intGuess As Integer
Public strGuess As String
End Structure
Private gameScore() As Integer
Private memoryGame(15) As MemoryBox
Dim countLoad As Integer = 0
Dim countScore As Integer = 0
Dim intScore As Integer
Private Sub LoadGame()
'this is where I am using the random numbers to make each box and populate it with a guess
Dim randomGen As New Random
Dim intMemBox As Integer
Dim intMemGuess As Integer
intScore = 0
If countLoad <= 15 Then
intMemBox = randomGen.Next(1, 16)
intMemGuess = randomGen.Next(1, 8)
memoryGame(countLoad).intBox = intMemBox
memoryGame(countLoad).intGuess = intMemGuess
memoryGame(countLoad).strGuess = intMemGuess.ToString
countLoad += 1
End If
End Sub
Private Sub GuessClick()
'trying to use this area for click event for each box click
lblMemory1.BackColor = Color.Green
lblMemory1.Text = memoryGame()
intScore += 1
lblScore.Text = intScore.ToString
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Call LoadGame()
End Sub
Private Sub btnNewGame_Click(sender As Object, e As EventArgs) Handles btnNewGame.Click
gameScore(countScore) = intScore
countScore += 1
Dim outFile As IO.StreamWriter
outFile = IO.File.AppendText("score.txt")
outFile.WriteLine(intScore)
outFile.Close()
Call LoadGame()
End Sub
Private Sub btnHighScore_Click(sender As Object, e As EventArgs) Handles btnHighScore.Click
Array.Sort(gameScore)
lblHighScore.Text = gameScore(0).ToString
End Sub
Private Sub btnAllScores_Click(sender As Object, e As EventArgs) Handles btnAllScores.Click
Dim inFile As IO.StreamReader
Dim strInfo As String
If IO.File.Exists("score.txt") Then
inFile = IO.File.OpenText("score.txt")
Do Until inFile.Peek = -1
strInfo = inFile.ReadLine
Loop
inFile.Close()
Else
MessageBox.Show("Can't find the score.txt file", "High Score", MessageBoxButtons.OK, MessageBoxIcon.Information)
End If
MessageBox.Show(strInfo, "All Scores", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub
End Class

Answer 1

One option is to populate an array with the numbers you want, then randomly shuffle it. Use a loop that runs at least one times the length of the array and use the iterator value as one index and swap it with a randomly chosen index.
Something like this:
Dim memoryGame(15) As MemoryBox
Dim randomarray() As Integer = {1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8}
Dim rnd As New Random(Now.Millisecond)
For I = 0 To 15
Dim randindex As Integer = rnd.Next(0, 16)
Dim temp As Integer = randomarray(I)
randomarray(I) = randomarray(randindex)
randomarray(randindex) = temp
Next
For I = 0 To 15
memoryGame(I).intBox = randomarray(I)
Next
From here simply iterate through the array and assign the values to your boxes
To handle the click events:
Use the same handler for each box. One way is to add a Handles clause for each box. With 16 boxes this could get a little clunky. I would suggest in the load event handler iterate through the boxes and use the AddHandler statement to add the handler to each box. At this point sender will always point to the box that was clicked. It is simply a matter of casting sender as whatever type the box is, to access all the properties of the box.
If the boxes are buttons(Box1, Box2, etc.) it would look something like this:
For Each b As Button In Me.Controls.OfType(Of Button).Where(Function(x) x.Name.StartsWith("Box"))
AddHandler b.Click, AddressOf Button_Click
Next
Private Sub Button_Click(sender As Object, e As EventArgs)
Dim clickedbutton As Button = DirectCast(sender, Button)
'access the properties here
End Sub