How to Stop reportProcessor.PrintReport()

[Fernando]

I want to be able to stop the execution of the ReportProcessor.PrintReport() and throw a custom error when the printer is unavailable (e.g: disconnected from the server) because instead of doing that the method is trying to find the printer and it freezes. if that's not possible a way to exit the method (timer?) would be good as well.

 

Regards,

 

Gaston.

 

[Todor]

Hello Gaston,

The ReportProcessor.PrintReport method may take a CancellationToken as an argument. You may start the report printing/rendering in a different thread and stop it from the main thread, for example, if it doesn't return a result in some time.

Regards,
Todor
Progress Telerik

[Fernando]

Hi Todor, thanks for your answer, do you have an example on how to use the cancellation token from the main thread to a secondary thread like that?

[Todor]

Hi Gaston,

I spoke with a developer, and he explained that the cancellationToken passed with the PrintReport method gets checked when the report is processed and rendered. When the printer is not available, report processing won't start, hence the checks in our code won't be hit. For that reason, we will suggest an alternative solution.

I have attached a sample Windows Forms project. On the Print button click, we open a new task called managerTask. The idea is to keep the UI thread unoccupied so that it doesn't hang and invoke printing from another thread instead. The managerTask thread starts the print task printingTask that is the actual printing. If printing takes more than expected (in this case 5s), the cancellation token will be set in the managerTask, and later, if printing continues, e.g. printer gets found, the printing will be canceled by our code.

The Trace Listener that is attached to the project logs how the printing has gone - see the App.config for the log file path. Note that we simulated unsuccessfully/slow printing with 'Thread.Sleep(10000);' and you need to remove this code.

Regards,
Todor
Progress Telerik