vb.net 2003: trying to speed up an owner-drawn listbox

[agent]

<shot in the dark>
maybe using BeginUpdate and EndUpdate will help to reduce the flickering?
</shot in the dark>

Actually, that increased the flickering to a horrible level whereas it's just bad now.

The way I had coded it was also pretty bad. To make it compatible with the way I intend to do things now, I have to re-write the code for that and in doing so, I'm going to double-buffer the whole thing to see if that works.

[The Dutch Dude]

Weird... BeginUpdate should stop the listbox from doing anything and display utterly nothing, a grey mass at the most, but it should not flicker. But I'll be interested to hear how this is solved..

[agent]

its mainly because the EndUpdate causes the whole thing to be re-drawn which causes all of the items to be redrawn. It doesn't call the drawitem event, but it does BeginUpdate...EndUpdate each time a new item is added or otherwise drawn.

[The Dutch Dude]

Ah, right, BeginUpdate should be placed before and EndUpdate should be placed after any adding takes place, then it should only redraw once, which is the point of the 2 methods, to stop the redrawing when an item is added.
So:

myBootaliciousListBox.BeginUpdate()
 
' example loop
while somethingOrOther
  myBootaliciousListBox.Items.Add(New ColorListItem("Text", Drawing.Color.Red)
end while
 
myBootaliciousListBox.EndUpdate()

[agent]

I'll give that a try...

Ah, right, BeginUpdate should be placed before and EndUpdate should be placed after any adding takes place, then it should only redraw once, which is the point of the 2 methods, to stop the redrawing when an item is added.
So:

myBootaliciousListBox.BeginUpdate()
 
' example loop
while somethingOrOther
  myBootaliciousListBox.Items.Add(New ColorListItem("Text", Drawing.Color.Red)
end while
 
myBootaliciousListBox.EndUpdate()