Applies To:
  • CitectSCADA 1.00 1.01 1.10 1.11 1.20 2.00 2.01

Question: When I close a form that is partly covering a Citect window, sometimes Citect will redraw the entire window and other times Citect will only redraw the section covered by the form. Why does this happen? 

When a form (or other window) that covered the Citect window is closed, Citect must decide if it can just redraw the section of the screen uncovered or must redraw the entire window. If the current Citect page does not have any colour fills, then Citect will just redraw the uncovered section. If the current page has one or more colour fills, then Citect must redraw the entire window. This occurs because a colour fill may start from outside the uncovered section and fill into the covered section. If Citect did not redraw the entire window then this colour fill would not be draw correctly.

If you want to stop Citect from repainting the entire window, avoid using colour fills. You can normally replace animation colours with animation symbols to get the same drawing effect. You can also try the option [Animator] MemDCPaint=1 to get a similar effect. This option will tell Citect to first draw the window into memory and then copy that memory to the screen. This will produce a similar effect however it does use more memory and may be slightly slower to display.