Ask the MultiValued Visual
Basic Expert - #2
(as published in Spectrum
magazine Jan/Feb 1997)
updated March
5, 1999
To email your questions to "Ask the MultiValued VB
Expert", click here.
Copyright © 1996-99 Caduceus Consulting. All rights reserved.
Using the Enter key to go from field to
field
We are rewriting our main data entry screen from a
character-based program on a uniVerse platform to Visual Basic.
Unfortunately our users are used to using the Enter key to move
from field to field, not the Windows standard Tab key. How can I
give them back their Enter key and are there any problems with
that? - A. Crocker, B & G Insurance
You raise an interesting issue. As a rule I counsel clients to
follow the established Windows standards as closely as possible.
Only by doing so do you take advantage of its universal
acceptance and gain a short learning curve for new users of your
application. However, despite Microsoft’s efforts, many
users, especially those trained in a character-based environment,
now use the Enter key instinctively. No matter how many copies of
Windows they have sold, the Enter key is still the biggest key on
everybody’s keyboard! Fortunately there is an easy solution,
giving them a choice of either the Tab key or the Enter key to
navigate from one field to the next.
Step one is to ensure that your data entry fields are in the
right tab order for your users to go from one to the next. This
is done by setting the TabIndex property of each control to
reflect the sequential order of the fields, beginning at 0.
Visual Basic allows you to capture key strokes using the
KeyPress event. To capture an Enter key (ASCII 13), you must
first ensure that there are no Command Button controls on your
form with a Default property of True. Otherwise, the Enter key
would click the Default button instead of going to the KeyPress
event.Rather than putting code on each control’s KeyPress
event, we can use one event for the whole form by setting the
Form control’s KeyPreview property to True. By doing so, all
of the keystrokes will now be sent to the Form_KeyPress event
first. Our objective is now to capture the Enter key and convert
it to a Tab key. So we have a start:
Sub Form_KeyPress (KeyAscii _ As
Integer)
....If KeyAscii = 13 Then
........<what goes here??>
....End If
End Sub
Note that simply changing KeyAscii from 13 to 9 will NOT work
- by the time it gets to the Form_KeyPress event it is too late
to treat KeyAscii as a Tab.
The trick is to send a Tab key, just as if the user had
pressed Tab instead of Enter, and then ignore the Enter key that
they did press, using the following code:
Sub Form_KeyPress (KeyAscii As
Integer)
....If KeyAscii = 13 Then
........SendKeys "{TAB}"
........KeyAscii = 0
....End If
End Sub
Bug Notice:
SendKeys "{TAB}" has been reported to occasionally
change the state of the CapsLock/NumLock keys in Visual Basic
version 5.0. Please use caution!
This code will work for most controls, with the exception of a
Command Button. If the current control (the one with Focus) is a
Command Button, then pressing the Enter key will always invoke
the Click event for that button and will NOT run our
Form_KeyPress code. This is probably what the user would expect
anyway, however, unless the Command Button takes the user out of
that form, you may want to move to a different control after the
button has been clicked. To do this, simply add the following
line at the end of the button’s Click event, where
“NextControl” is the name of the control to go to:
Sub Command1_Click()
....' <code for Click event>
....NextControl.SetFocus
End Sub
As a final enhancement, you may want the Enter key to still
give a new line when the user is in a TextBox whose MultiLine
property is set to True. If so, use the enhanced code shown below
(note that I put the code in its own library routine):
Sub Form_KeyPress (KeyAscii As
Integer)
....EnterAsTab KeyAscii
End Sub
Sub EnterAsTab (KeyAscii As
Integer)
If KeyAscii = 13 Then
....If TypeOf Screen.ActiveForm.ActiveControl
Is TextBox Then
........With Screen.ActiveForm.ActiveControl
............If .MultiLine Then
................If .Text = "" Then
....................' CR in empty box will become tab
................Else
....................' Needs 2 Enter keystrokes at end
....................' of text to exit text box.
....................If .SelStart <> Len(.Text) Then
........................' Cursor not at end of text...
........................Exit Sub
....................End If
....................If Right(.Text, 1) <> Chr(10) Then
........................' Previous char. not LF...
........................Exit Sub
....................End If
................End If
............End If
........End With
....End If
....SendKeys "{TAB}"
....KeyAscii = 0
End If
End Sub
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Expert", click here.
Copyright © 1996-99 Caduceus Consulting. All rights reserved.
Revised: March 5, 1999.
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