.Net Compact 3.5 custom controls slow to draw Colibri T30

Hi Guys

I have created a .Net 3.5 application in VS2008 that makes use of customs image controls (i.e. buttons, checkboxes). I have overridden the paint methods to overcome flicker problems providing double buffering and the controls function as expected.
These controls are subsequently used in UserControls where functionality can be grouped allowing me to swap UserControls when necessary.
My problem is that user controls that contain a large number of custom controls take some time to draw when showing the user control after it has been hidden. How can I speed up the drawing of these controls? Is there some way of accelerating the graphics draw? As mentioned I have no flicker issues, its the speed in which they are drawn. It takes about a 1.5 seconds to draw 30/40 custom controls.

Some help in this matter would be greatly appreciated.

Kind Regards

Hi Gareth

We are not .NET experts, so we might be the wrong people to ask this question.

You may want to try .NET CF V3.9. But this implies the use of WEC2013 and VS2013 or VS2015.
.NET V3.5 does only work on a single core, while V3.9 can use all 4 CPUs of the T30. I don’t know how much this would help and whether this is a valid solution for you.

Kind Regards, Andy

Hi Andy

I installed WEC2013 with VS 2013. I build the project and ran it but, there are serious issues with the Toradex.Net3.9 SDK when developing in VS. UserControls and CustomControls seemed to be rendered as unusable. They do not show in the VS ToolBox. A workaround was suggested here (https://www.toradex.com/community/questions/4957/ ), but this is not acceptable as it does offer any opportunity for debugging. Additionally, any time changes are made to ControlLibrary, requires compilation and re-adding the dll. However, if the control project is part of the same solution then this would mean closing the solution and restarting. I am wondering should I start a separate thread on the matter.

Anyways, many thanks for the suggestion, I was very hopeful that WEC 2013 would take care of the problem particularly that it makes use of multicore. But using WEC 2013 does not look like a viable option as the Tordaex 3.9 SDK does not facilitate the development of CustomControls or UserControls.

I’m not sure where to go from here!

Hi Gareth

I talked to a few people to collect some hints for you:

  • Unfortunately the VS2013/.NET V3.9 issues are part of Microsoft’s domain, where we don’t have access to fix any code.

  • There is no simple way to accelerate the drawing of user controls in .NET - .NET seems to be very inefficient in drawing user elements (pixel by pixel).

    • To accelerate it, you might have to mix native (C/C++) code with managed code.
    • If you drop us a demo project we can have a quick look at it. Maybe we can give you some more detailed hints where to start the optimization.

Kind Regards, Andy