Page 1
Page 2
' Handle the click event of all checkboxes
here.
' We know which control this came from based on
' the passed parameter.
Private Sub Check_Click(index As Integer)
' [ We will implement this later ]
End Sub
Private Sub Form_Load()
' Populate the fake control array
Set Check(0) = Check0
Set Check(1) = Check1
Set Check(2) = Check2
Set Check(3) = Check3
Set Check(4) = Check4
Set Check(5) = Check5
Set Check(6) = Check6
Set Check(7) = Check7
' [Place additional Form_Load code here]
End Sub
Next, let's add code to Form_Load that
will ask the user how many checkbox fields should be displayed
and creates an array of the value associated with each of
these fields.
' Ask how many fields to display
fields = CInt(InputBox("How many controls?", _
"Dynamic Control Simulation", 20))
' Resize the 'values' array to hold
' a value for each field
ReDim values(fields)
We will be altering the visible, caption,
and value property of the textboxes through a sub routine
called "UpdateView", so add the following to your
Form_Load and Scroll_Change methods:
' Update the UI
UpdateView
Now, we must implement UpdateView.
Given that we know the number of controls on the form and
the position of the scroll bar, we can easily pull information
from the right place in our "values" array and
configure the checkboxes accordingly.
Of course, the user may have scrolled
to a point where not all of controls have associated values.
When this happens, an "index out of bounds" error
occurs when we look in the "values" array. The
trick is to catch this error and make the unused controls
invisible:
Private Sub UpdateView()
' For each viewable field in record mode
Dim f As Integer
Dim val As Boolean
For f = 0 To 7
' See if there is a value for this field number.
' If not, an "index out of bounds" error will
' be generated.
On Error Resume Next
val = values(Scroll.Value + f)
' If there is no field here
If Err.Number <> 0 Then
' hide the checkbox
Check(f).Visible = False
' If there is a field
Else
' Display its value on the form
Check(f).Value = val
' Give it an appropriate caption
Check(f).Caption = "Control #" & _
CStr(Scroll.Value + f)
' Make sure its visible
Check(f).Visible = True
End If
Next
End Sub
Lastly, we will need to update the "values"
array when the user changes one of the controls. This is
easily done by implementing our Check_Change method with
a single line of code:
values(Scroll.Value + index) = Check(index).Value
This should be sufficient to get you
started. There are obviously many things you could do to
improve upon this, but I'll leave that to your imagination
and the kind people in the deVBuzz forums.
Previous Page