Question

i have a winforms application. i have a user control with a lot of icons. the user can load this control on a form many times (in a tabbed layout). right now i am loading the icons each time the control is created (could be up to 50 times in teh app). is there any way to cache these icons in the application. if i did this, would that decrease the number of gdi handles that i am using as this is becoming an issue.

Answer 1

You can make a singleton class for each icon. The first reference it creates the handle. Subsequent calls uses the existing handle.

Without knowing more about your user control my next suggestion can be only be very general. But you could have a single bitmap layer on which you draw all your icons. The remaining elements of your user control would exists above and around this bitmap.

Unfortunately this idea may be problematic performance wise. Require you to refactor the code you all ready use for arranging icons. Finally it is non-institutive from how frameworks with a control-form structure ideally works.

We ran into a resource problem with entry forms for the parameteric shape we ship with our CAM software. Too many text entries caused various forms of strangeness and leaks. So we instead created labels with borders that looked like text entries and had ONE text entry (and a combo box entry too). When the user tabs, enters, or clicked the single text entry moved to the new entry and the label was setup for the previous entry.

This is totally a non-intuitive setup than how you would normally code this but it was the only way to deal with our resource problem.

In my experience it seems that GUI Frameworks have issues when you have to deal with dozens or hundreds of entries and that you have to approach the problem using a different design.