Due to the lack of documentation, the only way I could figure out how these components work was to create a quick-and-dirty test harness. It consists of some Panel controls, a Splitter, and one each of the shell controls from the Samples palette, as shown in the screen shot below. There is nothing unusual going on with the form layout, so I want to move on to the interesting bits. You can check out the details in the Delphi 7 project files included in the download. Be sure to check out the Align property of the controls.

You will notice that the Object Inspector shows some properties, listed in red, that allow you to interconnect the shell controls at the click of a button. If you run the app without setting these, the controls work individually, but don't work together as they do in Windows Explorer. If, however, you use Object Inspector to set the ShellTreeView property of the ShellListView to point to your tree view, and the ShellComboBox property of the tree view to your ShellComboBox, you will see these three controls start working together.

Click, set, "connect"
Object Inspector conveniently offers links to the other controls in drop-down lists, so it is hard to go wrong. You will also see that, as you set up a link to a control, a link is automatically set up in the linked control, so that the interactions are reciprocal. While you are at it, have a look around at the other properties of these components. Some familiar ones are inherited from the underlying standard VCL controls; others, such as ObjectType and Root, are new. Play around a bit and see what they do.

On ShellChangeNotifier
So far, I haven't said anything about the ShellChangeNotifier control. This non-visual component provides simplified access to the native Win32 file system change monitoring facility. It turns out that the AutoRefresh property of the tree and list view controls provide this functionality automatically by creating an instance of the ShellChangeNotifier behind the scenes. I discovered this fact by poking around in the source code in ShellCtrls.pas. I urge you to look at this code for yourself-I know you will learn a lot.