Delphi 7 Win32 App display anomaly on Windows Vista

Posted on 2007-08-08
Last Modified: 2013-11-22
  A perplexing issue has arisen with running one of my Delphi 7 Win 32 apps. on Windows Vista. I recently introduced a 'constrainedresize' event into 4 similarly constructed forms within that app. These event handlers simply contain MinHeight and MinWidth constraints so that the user cannot scrunch them up below their optimum designed display. One and only one of these forms displays with about 30 to 40 pixels of the bottom chopped off, the others are fine ! This window contains a page control (as do the others) and successively selecting the page tabs progressively causes more and more of the window to be truncated at the bottom ! This is pretty weird stuff given the similarity between the forms.
  Does anyone have any ideas as to what might cause something like this (it's Vista specific)?
  How one window can be affected but not similar windows ?
  Ever seen anything like before ? cos I have no idea at all what may be going on here.


Question by:RetroRocker
    LVL 9

    Accepted Solution

    can you post dfm and pas files of this form?
    LVL 21

    Assisted Solution

    My guess is that you forgot to set the Message.Result to show that the message had been handled.  Without code to look at I can only guess though.

    Author Comment

    sas13 and developmentguru : thanks for the replies. I have uploaded the relevant dfm/pas files as suggested and they are available from EE-Stuff. There is also a link within the file comment there if you are possibly interested in seeing this display glitch during actual application execution - OK I know this app. might not exactly be your kind of thing but just in case ;-)
    One final thought, as it's Vista specific I wonder if 'aero graphics' could play a part in this ? If you do temporarily install the app. (it's small by present day standards but will install the BDE if you don't have it on the system already), you'll see that the other windows constructed similarly eg. airfields, flight sectors etc. don't possess this anomaly.

    Link :

    best wishes RR

    Author Comment

    sas13 and developmentguru : I owe you both a big apology, sorry ! Through some poorly contrived information received by me from a fellow developer, bad timing and assumptions on my part, I proposed this question completely unnecessarily. The bad information was as described earlier, the bad timing was in that until a couple of hours ago my Vista virtual machine was out of action but I have just managed to reinstate it (been having problems with host system random shutdowns), the assumption was in taking the information at face value.
      Bottom line is, this is nothing more than a horizontal scrollbar - arrggghhh !!! I suspect it is simply induced by having insufficient clientwidth for the size of the page control used due to the thicker window borders used by Vista - ouch ! What is more, I've found it in some other windows too - that will teach me to assume what I'm told is correct without checking first. It was not at all apparent from the screenshot I received, it just looked like a section of the bottom of the window was missing.
      So please disregard and thanks for at least coming back with the initial help. I think the most gracious thing I can do is simply split the points for your inconvenience suffered, close the thread, be embarassed and lose myself in that large hole that I am willing to open up !


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