Form.Invalidate(...)

[rliq]

Does anyone have any idea which of these is more efficient?

List<Rectangle> rectangles;
//some code to build the list (up to 56 rectangles)

// (1) is this the quickest?
foreach (Rectangle rect in rectangles)
  this.Invalidate(rect);

// (2) or is this?
Region region = new Region();

foreach (Rectangle rect in rectangles)
  region.Union(rect);

this.Invalidate(region);

OR... is it dependent on too many other factors to make a judgement?

Incidentally, in my scenario, if I use the region (2) option, then I don't need to build the list of rectangles beforehand, I can just add them to the region as they are created. This is because either the List<Rectangle> or the Region is returned from another function and not actually created in the same routine as in my example above.

[BigEd781]

Test test test, that is the best way to determine these things. however, If I had to guess, I would assume that option A would be quickest due to the simplicity of handling rectangles as opposed to amorphous regions. Maintaining a collection of rectangles is trivial.