Showing Progress Dialog in ArcGIS Desktop using ArcObjects?

Question

I have an ArcGIS custom IGPFunction tool. I want to use the GP progress dialog not the progress bar at the bottom of the ArcGIS 10 window as I don't want people to interact with the map whilst it's processing.

In the Execute method you have an instance of ITrackCancel but I can't work out how to show the default GP progress dialog from there. I have this as code at the moment but it still doesn't show the dialog. Any ideas?

        IStepProgressor pStepPro = (IStepProgressor)TrackCancel;
        pStepPro.MinRange = 0;
        pStepPro.StepValue = 1;
        pStepPro.Message = "Starting Import...";
        pStepPro.Position = 0;
        pStepPro.Show();

        ...

        pStepPro.Hide();

Answer 1

This is built-in to the Geoprocessing framework. If you have background processing turned on, you shouldn't block the UI. At all. It violates the principles of Geoprocessing -- what if you run the tool as a scheduled task, or in modelbuilder, or from Python?

If you absolutely HAVE to, two things:

• Pass the TrackCancel in to the ProgressDialogFactory.
• The ProgressDialog class -- use the IProgressDialog interface on to make visible, then use your regular StepProgressor logic on that instead.

I recommend checking if you're in a desktop application before bringing up a dialog by trying to create the AppRef class first -- if that fails, don't pop up a dialog.

But really, you shouldn't be second-guessing the user's preference for background/foreground processing. I'll assume in good faith you really do need this.