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AddressOf is indeed only for procedures (or possibly for
delagates?) Used to good effect, for example, when adding event
handlers dynamically with AddHandler (like when you want an array or collection
of withevent objects, and want single sub to handle the event from all the
objects in the collection).
One thing that may get overlooked here: ; ByVal and
ByRef are all well and good, but I think that for reference types the
distinction gets a little blurry.
A reference is like a pointer, in that it is actually the
memory address that refers to the 1st byte of the object.... so, while IRRC that
there IS SOME difference between referring to referrence types byVal or byRef, I
don;t think that it matters that much.... a ByVal argument sends the value of
the memory address... a ByRef argument sends... well... I'm not sure, but I
guess it must be a reference to the memory address? They seem to work
pretty similarly for refernce types.
I think you only need to change to byVal. (Or give up
on Option Strict) -- I tried out the following and it worked perfectly as
is. It also works fine with placecontrol accepting the ctrl argument ByRef
with Option Strict Off:
(draw in a textbox on the opening default form as
txt1. Add a button called button1 to a new project.)
Option Strict On
' Windows Form code
Private Sub placecontrol(ByVal
ctrl As Control,
ByVal Loc As Point)
ctrl.Location = Loc
End Sub
Private Sub Button1_Click(ByVal sender
As Object, ByVal e As System.EventArgs)
Handles Button1.Click
' place the textbox from
design mode
placecontrol(txt1, New Point(15,
35))
' dynamically create one and
place it.
Dim txt2 As New TextBox
txt2.Parent = Me
txt2.Size = New Size(100, 10)
txt2.Visible = True
txt2.BackColor = Color.Aqua
placecontrol(txt2, New Point(5, 5))
End Sub
I want pass a control to a procedure that will position the control on
the
form. I think the control needs to be passed ByRef. But when I
declare the
control argument to be ByRef, I get an error on the
calling end that says
"Strict Option will not allow the narrowing..."
First, am I correct
that I must pass ByRef? If so, what do I have to
do when I call. The
"AddressOf" operator says its only for
procedures?
Steve
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