Question

How can I implement shuffling of text on my button, i.e. text = chr(n+48) to shuffle text on each button.

Dim n As Integer = 0

For i As Integer = 0 To 10
    ' Initialize one variable
    btnArray(i) = New Button

Next i

While n < 10
    With btnArray(n)
        .Tag = n + 1 ' Tag of button
        .Width = 40 ' Width of button
        .Height = 40
        .Text = Chr(n + 48)
        FlowLayoutPanel1.Controls.Add(btnArray(n))
        AddHandler .Click, AddressOf Me.GenericClickHandler
        n = n + 1
    End With
End While

Answer 1

I don’t know if there is a reason why you are doing that to two steps.
Try something like this:

Private btnArray As New List(Of Button)

For i As Integer = 0 To 10
    Dim btn As New Button
    With btn
       .Tag = i ' Tag of button
       .Width = 40 ' Width of button
       .Height = 40
       .Text = Chr(i + 48)

    End With  
    btnArray.Insert(i, btn)

   'FlowLayoutPanel1.Controls.Add(btnArray(i))  'It works also
    FlowLayoutPanel1.Controls.Add(btn)
    AddHandler .Click, AddressOf Me.GenericClickHandler

Next i

Based on your comments:

Private btnArray As New List(Of Button)
Private btnShuffleArray As New List(Of Button)

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
    For i As Integer = 0 To 10
        ' Initialize one variable
        Dim btn As New Button
        With btn
            .Tag = i ' Tag of button
            .Width = 40 ' Width of button
            .Height = 40
            .Text = Chr(i + 48)
            btnArray.Insert(i, btn)
            '   FlowLayoutPanel1.Controls.Add(btnArray(i))
            'AddHandler .Click, AddressOf Me.GenericClickHandler
        End With
    Next i

    'Randomize the list
    Dim rand As New Random
    Dim index As Integer
    While btnArray.Count > 0
        index = rand.Next(0, btnArray.Count)
        btnShuffleArray.Add(btnArray(index))
        btnArray.RemoveAt(index)
    End While

    For i = 0 To 10
        FlowLayoutPanel1.Controls.Add(btnShuffleArray(i))
    Next

End Sub