How to add event handler to a dynamically created control in VB.NET? - vb.net

Question

I have searched and seen countless samples here in this forum and in other sites but I'm still stuck with this problem;
I want to add a Click Handler for dynamically created PictureBox-es and pas an argument on it so I know which one of picture boxes was clicked).
Here is my current code:
Public Class frmMbarimAbonimi
Private Sub frmMbarimAbonimi_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'FitnessdbDataSet.clients' table. You can move, or remove it, as needed.
'Me.ClientsTableAdapter.Fill(Me.FitnessdbDataSet.clients)
'===============
Dim dt As DataTable = PaPaguar()
Dim i As Integer = 0
Dim gr(dt.Rows.Count) As GroupBox
Dim pp(dt.Rows.Count) As PictureBox
Dim lb(dt.Rows.Count) As Label
For Each row As DataRow In dt.Rows
gr(i) = New GroupBox
gr(i).Width = 200
gr(i).Height = 180
pp(i) = New PictureBox
pp(i).SizeMode = PictureBoxSizeMode.StretchImage
lb(i) = New Label
'-------------------------
Try
Using str As Stream = File.OpenRead("C:\Fotot\" + dt.Rows(i).Item("Foto"))
pp(i).Image = Image.FromStream(str)
End Using
lb(i).Text = dt.Rows(i).Item("Emer")
Catch ex As Exception
MsgBox("Fotoja nuk mund te ngarkohet, ju lutem realizoheni nje foto tjeter!!!")
End Try
'-------------------------
pp(i).Visible = True
pp(i).Width = 200
pp(i).Height = 150
AddHandler pp(i).Click, AddressOf testini
gr(i).Controls.Add(pp(i))
lb(i).Visible = True
lb(i).Width = 200
lb(i).Height = 30
lb(i).Left = pp(i).Left
lb(i).Top = pp(i).Top + 150
lb(i).BackColor = Color.WhiteSmoke
lb(i).BringToFront()
gr(i).Controls.Add(lb(i))
flpanel.Controls.Add(gr(i))
i = i + 1
Next row
End Sub
End Class
So I was trying to use AddHandler pp(i).Click, AddressOf testini but obviously this does not allow me to call "testini" with a parameter to identify which picture box was clicked.
Can someone point me in the right direction or give some advice? Greatly appreciated.

Answer 1

You need to add something to your created PictureBox to identify them in the event handler because you can't change the signature of the click event handler adding a 'parameter'
For example, you could set the Name property
pp(i) = New GroupBox
pp(i).Name = "PictureBox" + i.ToString
then in the event handler you could recognize your picture box casting the sender object to a picturebox and grabbing the Name property.
Remember, sender is always the control that triggers the event. In your case is always one of your dinamically created PictureBoxes
Private Sub testini(sender As Object, e As System.EventArgs)
Dim pb As PictureBox = DirectCast(sender, PictureBox)
Dim pbIdentity As String = pb.Name
.....
End Sub