My tabbing ain't working

If you're opening your forms like this:

frmNewForm.Show()

then you're opening a modeless dialog, and may experience some strange behaviour. The most prominent of these is the loss of the tab button - your users won't be able to tab through controls on the form.

To overcome this, you need to use this:

frmNewForm.ShowDialog()

which opens a modal dialog, and all expected functionality is available. But then your users can't interact with Revit until it is closed.

So I'm faced with a bit of a trade-off. Some of my forms are modal, and those that require the user to interact with Revit are modeless, which means that tabbing and other functionality (the Delete key is another) is lost. I'm lucky in that it hasn't caused too many problems, but I wonder how many programmers find this a real pain?