Detecting Print in Outlook (VSTO/C#)

This is a common problem in Outlook. You might have tried to override the Ribbon settings for Print in Outlook to find that your code never gets run when the user clicks Print.

There is also not any events in the Outlook object model to detect Print either. So if you need to detect the user pressing the print button, you are out of luck.

While it is still not possible to detect the print button being pressed, you can at least detect when the user has selected the Print tab on the backstage.

The following code uses a background thread and a series of Windows API calls to FindWindow/FindWindowEx to detect when the Print tab on the backstage is opened:

An Asynchronous MessageBox

Recently, I had a project I was working on where we needed to be able to notify the user of a possible problem during a long running process. The results would not be ruined, or wrong, just likely incomplete. In this particular case we were collecting several pieces of information and sometimes one of those pieces were not available (say, for example the server was down, the file was missing, or it took too long). We wanted to let the user know the process had encountered an issue, but not stop it. Yet we wanted to also give them the option to retry it. So we presented an Abort, Retry, Cancel dialog like this one:

messagebox

The problem is that with a traditional MessageBox the entire process would be frozen. If this happens immediately after the user heads off to lunch, when they get back there would be no report, no data and most of the process would not have been run yet, for example.

What I needed was for the process to continue, but to allow the user to be able to take action before the process completed on anything that was found. For example, they see this error above and think: “oh crap, I forgot to copy over the report file.” So they put the correct file in place and hit “Retry.”

Therefore, I created the AsyncMessageBox class:

Under the covers this uses a traditional MessageBox, but on background thread. You need to attach to the MessageBoxClosed event before you make the AsyncMessageBox.Show() call if you want to get the result. Here is how you use this method:

Anyway, thought this might be useful, so I have shared it. wlEmoticon-hotsmile.png