"Casting" an object in Microsoft Access

[Vincent]

Regarding the dropdetect function, defined as follows:

Sub dropdetect(DropFrm As Form, DropCtrl As Control, Button As Integer,
Shift As Integer, X As Single, Y As Single)

Is it possible to cast the Control parameter, DropCtrl, to a TextBox
object? The underlying control is in fact a textbox which I wish to
redraw given the X and Y parameters above. In Java, you could simply
declare a TextBox reference and assign it to the Control object as
follows:

Dim myTextBox as TextBox
myTextBox = (TextBox)DropCtrl

Is there any analogous code in VBA? Thanks.

-Vincent

[Allen Browne]

Try:
Dim myTextBox as TextBox
Set myTextBox = DropCtl

Anything you can do with a TextBox object, you should also be able to do
directly with a Control object anyway, so I'm not sure why you would need to
do that.

--
Allen Browne - Microsoft MVP. Perth, Western Australia.
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.

"Vincent" <an**********@verizon.net> wrote in message
news:11**********************@i39g2000cwa.googlegr oups.com...

Regarding the dropdetect function, defined as follows:

Sub dropdetect(DropFrm As Form, DropCtrl As Control, Button As Integer,
Shift As Integer, X As Single, Y As Single)

Is it possible to cast the Control parameter, DropCtrl, to a TextBox
object? The underlying control is in fact a textbox which I wish to
redraw given the X and Y parameters above. In Java, you could simply
declare a TextBox reference and assign it to the Control object as
follows:

Dim myTextBox as TextBox
myTextBox = (TextBox)DropCtrl

Is there any analogous code in VBA? Thanks.

-Vincent

[david epsom dot com dot au]

You can only do implicit casting by assigning
the object to a variable of different type

That is, you can do implicit casting without
a cast operator:

Dim myTextBox as Access.TextBox
set myTextBox = DropCtrl

or

Sub dropdetect(DropFrm As Form, _
DropCtrl As Access.Textbox, _
Button As Integer, _
Shift As Integer, _
X As Single, Y As Single)
(david)

"Vincent" <an**********@verizon.net> wrote in message
news:11**********************@i39g2000cwa.googlegr oups.com...

Regarding the dropdetect function, defined as follows:

Sub dropdetect(DropFrm As Form, DropCtrl As Control, Button As Integer,
Shift As Integer, X As Single, Y As Single)

Is it possible to cast the Control parameter, DropCtrl, to a TextBox
object? The underlying control is in fact a textbox which I wish to
redraw given the X and Y parameters above. In Java, you could simply
declare a TextBox reference and assign it to the Control object as
follows:

Dim myTextBox as TextBox
myTextBox = (TextBox)DropCtrl

Is there any analogous code in VBA? Thanks.

-Vincent

[Terry Kreft]

When casting you really should test that the interface is supported which
you do uing the TypeOf predicate you can then simply assign variable to
variable as follows:-

Dim myTextBox as TextBox

If TypeOf DropCtrl is textbox then
Set myTextBox = DropCtrl
' ...
Else
' Do something else because it's not a textbox
end if
--

Terry Kreft
"Vincent" <an**********@verizon.net> wrote in message
news:11**********************@i39g2000cwa.googlegr oups.com...

Regarding the dropdetect function, defined as follows:

Sub dropdetect(DropFrm As Form, DropCtrl As Control, Button As Integer,
Shift As Integer, X As Single, Y As Single)

Is it possible to cast the Control parameter, DropCtrl, to a TextBox
object? The underlying control is in fact a textbox which I wish to
redraw given the X and Y parameters above. In Java, you could simply
declare a TextBox reference and assign it to the Control object as
follows:

Dim myTextBox as TextBox
myTextBox = (TextBox)DropCtrl

Is there any analogous code in VBA? Thanks.

-Vincent

[Terry Kreft]

Very early binding which gives a performance increase (I know, I know it
won't even be noticeable but I had to give the _correct_ answer first)

Probably more important to some is that casting to the correct interface
then gives you the correct information in the context sensitive drop-downs
in the editor.
--

Terry Kreft
"Allen Browne" <Al*********@SeeSig.Invalid> wrote in message
news:44***********************@per-qv1-newsreader-01.iinet.net.au...

Try:
Dim myTextBox as TextBox
Set myTextBox = DropCtl

Anything you can do with a TextBox object, you should also be able to do
directly with a Control object anyway, so I'm not sure why you would need to do that.

--
Allen Browne - Microsoft MVP. Perth, Western Australia.
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.

"Vincent" <an**********@verizon.net> wrote in message
news:11**********************@i39g2000cwa.googlegr oups.com...

Regarding the dropdetect function, defined as follows:

Sub dropdetect(DropFrm As Form, DropCtrl As Control, Button As Integer,
Shift As Integer, X As Single, Y As Single)

Is it possible to cast the Control parameter, DropCtrl, to a TextBox
object? The underlying control is in fact a textbox which I wish to
redraw given the X and Y parameters above. In Java, you could simply
declare a TextBox reference and assign it to the Control object as
follows:

Dim myTextBox as TextBox
myTextBox = (TextBox)DropCtrl

Is there any analogous code in VBA? Thanks.

-Vincent