I was so sure that there just has to be a way to force the plus sign (+) displayed on the TreeView WinForm control - but looks like I was wrong. The TreeView control intelligently decides to show the plus and minus signs depending on whether a node has child nodes or not and whether they are expanded or collapsed. The problem with this design is that it assumes that the control will always know the full tree hierarchy that a user is trying to display. In scenarios where you have a very large list of objects (nodes) to be shown, it might improve performance to not load or retrieve that list till absolutely necessary. So you would want to display a + sign next to a node, irrespective, of whether it has child nodes or not. When the user clicks on the node, the sign can be cleared away if there are no child nodes to be displayed. This is exactly the behavior of the IIS Manager MMC and it seems like it is not possible to do this with the Out-Of-The-Box TreeView control. This is further exacerbated if the data you are retrieving is over a web service (which should become more prevalent as time goes by) – so you would never want to get the full tree details in the very first call that you make.
Am I missing something here? Anyone know of an extended TreeView control which has this option/behavior?