Create controls at run time with events

'                                                                                               
'  Name:                                                                                        
'                                                                                               
'    DynamicTextBoxes                                                                           
'                                                                                               
'  Description:                                                                                 
'                                                                                               
'    Simple example of how to create and use textboxes at run time. The number of rows and      
'    columns of textboxes are defined by ROWS and COLS. The spacing between controls is defined 
'    by XPAD and YPAD. The control size is defined by TBWIDTH and TBHEIGHT and the location of  
'    the control at the top left is defined by XSTART and YSTART.                               
'                                                                                               
'  Audit:                                                                                       
'                                                                                               
'    2012-05-20  Reverend Jim                                                                   
'                                                                                               

Public Class Form1

    Const XPAD = 5          'horizontal spacing between controls
    Const YPAD = 5          'vertical spacing between controls  
    Const ROWS = 5          'number of rows of textboxes        
    Const COLS = 5          'number of columns of textboxes     

    Const TBWIDTH = 100     'text box width                     
    Const TBHEIGHT = 20     'text box height                    
    Const XSTART = 10       'x position of first text box       
    Const YSTART = 10       'y position of first text box       

    Private boxes(ROWS, COLS) As TextBox

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load

        Dim newbox As TextBox

        'create a grid of textboxes

        For row As Integer = 0 To ROWS - 1
            For col As Integer = 0 To COLS - 1

                'calculate the position of the nex textbox

                Dim xpos As Integer = XSTART + row * (XPAD + TBWIDTH)
                Dim ypos As Integer = YSTART + col * (YPAD + TBHEIGHT)

                'create a new textbox and set its properties

                newbox = New TextBox
                newbox.Size = New Drawing.Size(TBWIDTH, TBHEIGHT)
                newbox.Location = New Point(xpos, ypos)
                newbox.Name = "TextBox" & row & "_" & col
                newbox.Text = newbox.Name

                'connect it to handlers, save a reference to the array and add it to the form controls

                AddHandler newbox.TextChanged, AddressOf TextBox_TextChanged
                AddHandler newbox.Enter, AddressOf TextBox_Enter

                boxes(row, col) = newbox
                Me.Controls.Add(newbox)

            Next
        Next

    End Sub

    Private Sub TextBox_TextChanged(sender As System.Object, e As System.EventArgs)

        'when you modify the contents of any textbox, the name of that textbox and
        'its current contents will be displayed in the title bar

        Dim box As TextBox = DirectCast(sender, TextBox)
        Me.Text = box.Name & ": " & box.Text

    End Sub

    Private Sub TextBox_Enter(sender As System.Object, e As System.EventArgs)

        'when you enter a textbox control, its current contents will be displayed
        'in the title bar

        Dim box As TextBox = DirectCast(sender, TextBox)
        Me.Text = box.Name & ": " & box.Text

    End Sub

End Class