create function for sender object handler - vb.net

Question

how do i create a function for a sender as object click? I tried something, but it didn't work out.
Private Function functionName(ByVal sender As Object, e As EventArgs)
If sender.checked = True Then
For i As Integer = 2 To 14
If i <> 2 Then
Dim cbClubs = DirectCast(Controls.Item("cbBtt" & i & "detrefla"), CheckBox) 'Clubs
cbClubs.Checked = False
End If
Next
End If
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
functionName(cbBtt2detrefla, sender)
End Sub

Answer 1

Let's put some order in this code.
Private Function functionName(ByVal sender As Object, e As EventArgs)
'...
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
functionName(cbBtt2detrefla, sender)
End Sub
Why are you using e As EventArgs in functionName(...) declaration? It's never used, so u can delete it:
Private Function functionName(ByVal sender As Object)
In functionName you are evaluating sender.Checked (a tip: you can use If sender.Checked instead of If sender.Checked = True): why not to define sender as CheckBox, instead of Object?
Private Function functionName(ByVal sender As CheckBox)
Now, let's see the for Loop:
For i As Integer = 2 To 14
If i <> 2 Then
'...
End If
Next
You are evaluating i from 2 to 14, but you don't want to do anything if i = 2. Why not to start the for loop from i=3? It's faster and better.
For i As Integer = 3 To 14
'...
Next
Another thing: functionName() doesn't produce an output, so it should be a Sub, not a Function.
Now, your code is:
Private Sub functionName(ByVal sender As CheckBox)
If sender.Checked Then
For i As Integer = 3 To 14
'...
Next
End If
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
functionName(cbBtt2detrefla)
End Sub
Furthermore, if functionName is called only by Button1_Click and here it is only used with cbBtt2detrefla, you can avoid separating the two subs:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If cbBtt2detrefla.Checked Then
For i As Integer = 3 To 14
'...
Next
End If
End Sub
Last, but not least:
Dim cbClubs = DirectCast(Controls.Item("cbBtt" & i & "detrefla"), CheckBox) 'Clubs
cbClubs.Checked = False
This works only if cbBtt3detrefla and the others checkBoxes are directly on the form. If they are in a Panel, for example, you'll get a System.NullReferenceException. If you want to iterate on every control, you can do something like this.