How are you building the canvas to scroll?
What I have done in the past is construct a canvas or canvases within a
canvas and draw into the internal canvas or canvases. I scroll the
internal canvas or canvases with a scrollbar by setting the Top property
of the internal canvas or canvases in relation to the scroll value.
Because the canvas or canvases are a child of another canvas the parts
you do not want to display are outside the visible area of the parent
canvas and the redraw of the internal canvas or canvases or even other
controls are handled automatically. Here is some code I used for an
array of canvases enclosed in another canvas.
Dim i,n,s,theTop As Integer
s = Me.Value
// numcanvases is a global integer variable
// holds the number of canvas controls I have
// created in the canvas array
n = (numcanvases -1)
// 36 is the window.open top value for the internal canvas
theTop = (36 - s)
theCanvas(0).Top = theTop
For i = 1 To n
theTop = (theTop + 420)
// 420 is the LineStep value I set for this scrollBar
theCanvas(i).Top = theTop
Next
HTH
Tom
> How do people find out what portion of a canvas needs to be
> drawn when calling a canvas.scroll with only a portion being
> scrolled? And is it possible to tell the canvas not to erase
> that portion?
>
> thanks
>
> AC
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