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Unexpected double-click events RRS feed

  • Question

  • Hello,

    I'm investigating a problem where it seems that the "virtual keyboard" of our customers application "looses" some inputs when touching/clicking the same button multiple times in a short time. "Typing" the value "0000" at a rate of 4 hits/seconds we only recieve "00".

    While looking deeper into I found out that the problem occours only when the "virtual keyboard" within the application. Our test-installation seems to use the same "virtual keyboard". "Spy++"-ing the buttons we see a usual WM_LBUTTODOWN/WM_LBUTTONUP sequence in the "well working" test-installation - on the failing device we also recieve the usual WM_LBUTTODOWN/WM_LBUTTONUP sequence, but additionally is followed by a WM_LBUTTONDBLCLK/WM_LBUTTONUP sequence.

    At this point I have to add that the problem does not affect all devices - we recieved on of them from customer, they told us that the problem did not occour on the replacment device (we hope they meant by performing the exact tasks as they did on the "failing" one). For information - we deliver device with pre-installed WES7 O/S, while customer add their frontend appliation and probably others. The front-end is a VB6 application - I know that such applications are not supported by Windows 7, but it seems to work so far.

    We initally assumed a problem with the touchscreen, but the same bevahiour can be seen by doing the same with a (extanal USB) mouse. We also copied the contents of the "failing" device to another that worked fine with a test-installation (similar to the failing configuration), now the problem occoured on this device too. With short word: The problem moves with the SW.

    Does anyone have an idea? Have much thanks in before.

    With best regards,
    Willi K.

    Monday, July 13, 2015 3:41 PM

All replies

  • Is this the same Virtual Keyboard that comes with WES7?

    What is the background processor load? is there an app or service that is consuming resources at the time for using the virtual keyboard?

    Anyway to set the affinity for the keyboard - http://www.techrepublic.com/blog/windows-and-office/change-the-processor-affinity-setting-in-windows-7-to-gain-a-performance-edge/ ?


    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Tuesday, July 14, 2015 12:03 AM
    Moderator
  • Hello Sean,

    thanks for your inputs. The "Virtual Keyboard" is NOT the one that comes with WES7 - it is implemented into the front-end application (i will call it the "VBVK"). The argument that something may be wrong within the application was recjected by the fact that there are systems that does not show the problem (I think we all know customer's common reactions).

    Regarding system load I monitored the system's and application's CPU load etc. using ProcessExplorer, but nothing special happens when "typing" with the "VBVK". I think you assume that a process etc. "blocks" some input (windows messags) - as mentoined above there additional window messages (events) will arise.

    Tuesday, July 14, 2015 7:36 AM
  • After "some" extra tests I found a resolution for the problem. The kind of solution is  very confusing since it seems that there is no logical relation between the symptoms and the solution:

    As already mentoined, our customer installed some additional SW. We recieved the setups for that software from them in order to be able to repeat their entire configuration process. Initially it looked like everything works fine after all the SW components have been installed, the problem did not occour.

    For some reason I performed a EWF commit command for drive C: (EWF was already enbled - enabling EWF for C: was one of the last steps of the configuration process). From this moment (after a system restart - of course) the problem occoured and persists.

    Now it comes:
    I already heared that there was something with EWF and TRIM commands on SSD. Looking at the symptoms it sound crazy, but in my situation I clutched at a straw and gave i a try, and disabled TRIM before performing customer's configuration process. VOILA - the problem did not occour any more.

    Can anybody see and - of course - explain what is going on here? What is stored in EWF or "written through" by TRIM command that deals with the messages that are sent to a window?

    Thursday, July 16, 2015 8:18 PM