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New Blog Posts: Merging Reports - Part 1 and Part 2

Attaching events

edited October 2003 in RAP
I have 2 reports on 1 form where I am using a template on the second report.
When I attach the OnPreviewFormCreate procedure to the second report, Delphi
does not recognize it, and I get either an access violation or the report
comes up small, just like I didnt even attach the OnPreviewFormCreate
procedure to it. Is there any type of code or special procedure that will
attach this event to the report I am using the template on?

Johndrea Thompkins

Comments

  • edited October 2003
    --------------------------------------------
    Article: Troubleshooting Lost Event Handlers
    --------------------------------------------

    Let's assume you have created a report in Delphi and assign an event
    handlers to the OnPreviewFormCreate event of the report. The event is
    generated by Delphi as:

    procedure TForm1.ppReport1PreviewFormCreate(Sender: TObject);

    You then save the report to an RTM file 'Report1.RTM.' The events are
    stored as references only, and so the RTM contains:

    object ppReport1: TppReport
    .
    .
    OnPreviewFormCreate = ppReport1PreviewFormCreate
    end

    You then go on to work on a different report. Saving it with under then
    name 'Report2.RTM'. Only this time, before you save the report you change
    the report component name to: rptOrders. Delphi automatically updates the
    event declaration for OnPreviewFormCreate event to:

    procedure TForm1.rptOrdersPreviewFormCreate(Sender: TObject);


    You then create two buttons on the form, one to load Report1 and preview,
    the other to load Report2 and preview. When you run the app and click
    Report1, you an error. This is because the Report1.RTM file contains a
    reference to ppReport1PreviewFormCreate, a method which no longer exists (at
    least with this name) in the form.

    One answer is to load all your rtm files into the report component you will
    be using for loading. Fix any errors, reassign any events that get cleared.
    This will update your rtms to contain the proper event handler names.


    --
    Best Regards,

    Nico Cizik
    Digital Metaphors
    http://www.digital-metaphors.com
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