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New screen combobox do not go up at edge of screen RRS feed

  • Question

  • Hi,

     WinCE 6.0 VS2005

    Have fitted a new size screen to our board and set it up in the registry.

    The OS shell appears to have resized correctly. The problem is that when a combo box nears the edge of the screen now

    instead of changing direction and scrolling upwards. They now scroll down and off the screen.

    The application is a managed app, but I assume this is an OS platform builder issue.

    thankyou.

    /Ashley

    Monday, May 7, 2012 8:07 AM

Answers

  • It's not just the registry that has to change. The display driver has to know the dimensions of the screen *and* the data format to the display controller to make that happen. While it's possible that the generic system display size information is used, that would be unusual in my experience.

    Most of the display drivers are built specifically for one LCD display, meaning a *very* specific horizontal and vertical size and orientation (x pixels by y pixels, determined by the number of transistors in the display glass). For rotation to work, the display driver must also support it (and do so correctly).

    It sounds like you've told Windows CE that the desktop display is bigger than it actually is. Windows CE doesn't care; it will gladly draw off the screen...the display itself however is not infinitely rescalable and may not even know that you want it to change!

    Paul T.

    • Marked as answer by ttBlue Wednesday, February 18, 2015 4:28 PM
    Wednesday, May 30, 2012 6:02 PM

All replies

  •  I noticed the the combobox issue occurs only when in landscape mode...

    Which is controlled by the following code and not the LCD driver..

                 Angle = Angle % 360;
                RegistryKey reg = Registry.LocalMachine.OpenSubKey(@"\System\GDI\Rotation", true);
                reg.SetValue("Angle", Angle, RegistryValueKind.DWord);
                int value = (int)reg.GetValue("Angle", 0);
                reg.Flush();

    Still confused as to why the comboboxes go off screen though..

    /Ashley

    Thursday, May 24, 2012 10:01 AM
  • It's not just the registry that has to change. The display driver has to know the dimensions of the screen *and* the data format to the display controller to make that happen. While it's possible that the generic system display size information is used, that would be unusual in my experience.

    Most of the display drivers are built specifically for one LCD display, meaning a *very* specific horizontal and vertical size and orientation (x pixels by y pixels, determined by the number of transistors in the display glass). For rotation to work, the display driver must also support it (and do so correctly).

    It sounds like you've told Windows CE that the desktop display is bigger than it actually is. Windows CE doesn't care; it will gladly draw off the screen...the display itself however is not infinitely rescalable and may not even know that you want it to change!

    Paul T.

    • Marked as answer by ttBlue Wednesday, February 18, 2015 4:28 PM
    Wednesday, May 30, 2012 6:02 PM
  •  Hello Paul,

     Thankyou for the response. 

     When I built the OS image I included a driver that appears to have the same dimensions as my screen (480x272).

    BSP_DISPLAY_ET0430G0DH6_480x272x16 BSP_DISPLAY_CONFIGURABLE_DISPLAY_DRIVER

    My screen is a Tianma LCD. 

    The OS shell does appear to fit the screen exactly as expected when it is rotated (The task bar is fitted along the bottom of the screen).

    Just the comboboxes that don't seem to know.

    From what you say I need to contact the LCD manufacturer - Which I will do, crossing my fingers that they have a driver and

    I don't have to write one.

    /Ashley.

    Sunday, June 3, 2012 4:42 PM