Example of Using the "OnBeforePrint" Event

Example of Using the "OnBeforePrint" Event

To demonstrate this event create a report representing a list of clients. This report will include only those companies whose name begins with the letter "A".

Let's create a new project, place "TfrxDlDBTable" component on the form and set these properties:

UserName = 'Subjects'

Open the report designer and create a report like this:

Select the data band and switch to the “Events” tab in the object inspector:

To create an “OnBeforePrint” event handler (which is the most appropriate for us) double-click on the blank field to the right of the event’s name:

This adds a blank handler to the script and the designer switches to the “Code” tab.

All that is needed now is to type the following code in the handler’s body:

if  Copy(<Subjects."acSubject">, 1, 1) = 'A' then

  MasterData1.Visible := True

else

  MasterData1.Visible := False;

Run the report and make sure that the script works correctly:

Let's explain several things. One handler can be assigned to the events of more than one object - the “Sender” parameter shows which object has initiated the event. To assign an existing handler to an event, either type it directly into the object inspector, or select it from the drop-down list:

A link to a handler can be easily deleted - select the assigned handler in the object inspector and press the “Delete” key.

If event handler is deleted code still remains on the report but it is not used. It only event handler remains also no code is executed and no error occurs.