TmoDBNav FAQ

Updated 8/4/96

this is a picture of the navigator


Table of contents


+Resource file problems
+Problems compiling
+Problems with Vertical orientation
+Invalid Pointer Operation message
+GP Fault
+Back to the TmoDBNav page
+Back to Maggie's Home Page


Resource file problems

If you downloaded the TmoDBNav from any location before July 14, 1996, the .pas file contains incorrect information about the resource file. (Oops! I uploaded the wrong version to both locations.) There are two ways to fix this:

  • Download the newer version from the TmoDBNav page.
  • OR insert the following lines of code after the implementation: 
      {$IFDEF VER80}
    {$R dbnav16.RES}
  {$ENDIF}
  {$IFDEF VER90}
    {$R DBNAV32.RES}
  {$ENDIF}


    Problems compiling

    If you are using both Delphi 16 and Delphi 32, you cannot use the same copy of the navigator for both, because the .dcu file that is created when you compile is not compatible between the two. Keep two different copies, preferably with the same name, but in two different directories, so that you don't have to change the name in the uses when you upgrade (or downgrade) your application.



    Problems with Vertical orientation

    In versions prior to 1.1, there was a bug with the vertical orientation. This has been corrected. Please make sure you have a version dated 7/25/96 or later, or download the latest one.


    Invalid Pointer Operation message

    In Delphi 2.0, you will get this message upon closing a form with the TmoDBNav on it, if you have clicked the Set Bookmark button and have not released the bookmark by clicking the Clear Bookmark button. I am working on this one, and hope to update the component soon. For the time being, you should not be concerned, as the resource leakage resulting from this is negligible. If you're trying to deliver an application using this component, and must get rid of this message, find the following code in the destructor TmoDBNav.Destroy: 

      if FBookmark <> nil then
    Dispose(FBookmark);
    and wrap it in a try..except, like this: 
      if FBookmark <> nil then
    try
      Dispose(FBookmark);
    except
    end;



    GP Fault

    If you dynamically reset the navigator's DataSource property or any of its other properties at runtime during the OnClick or OnEnter event handler of another component or during the Screen's OnActiveControlChange event handling procedure, you must make sure that 

      moDBNav1 <> nil
    before doing so, or you will get a GP fault when the form closes. This is normal Delphi behavior -- it will also occur with any component treated in this manner, including the TDBNavigator.



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    ©1996 Maggie Owens.