{"id":93705,"date":"2016-06-20T07:00:00","date_gmt":"2016-06-20T21:00:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/oldnewthing\/?p=93705"},"modified":"2019-03-13T11:51:12","modified_gmt":"2019-03-13T18:51:12","slug":"20160620-00","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20160620-00\/?p=93705","title":{"rendered":"Peeking inside an IShellItem to see what it’s made of"},"content":{"rendered":"

Windows XP introduced the IShell­Item<\/code> interface<\/a> which represents an item in the shell namespace. This encapsulates what traditionally is represented by a pair of things<\/a>, the the IShell­Folder<\/code> interface<\/a> and an ITEMID_CHILD<\/code><\/a>. The shell item lets you carry just one object around instead of two. <\/p>\n

Another way of representing an item in the shell namespace is in the form of a single ITEMID_ABSOLUTE<\/code>, and you can also create a shell item from that. <\/p>\n

Creating a single unit of currency to represent a shell item tries to solve the problem of having to exchange money every time you cross a boundary<\/a>. The IShell­Item<\/code> also gives you some methods which simplifies various operations by wrapping low-level methods on IShell­Folder<\/code>. For example, the IShell­Item::Bind­To­Handler<\/code> method figures out the right way to get the item you ask for rather than making you puzzle out the arcane rules behind IShell­Folder::Bind­To­Object<\/code>, IShell­Folder::Bind­To­Storage<\/code>, IShell­Folder::Create­View­Object<\/code>, IShell­Folder::Get­UI­Object­Of<\/code>, and more. <\/p>\n

But what if you need something that IShell­Item<\/code> doesn’t provide a convenience wrapper for? Then you need to peek inside. <\/p>\n

If you want to peek inside and get the IShell­Folder<\/code> and ITEMID_CHILD<\/code>, you can use the IParent­And­Item<\/code> interface<\/a>, specifically, the IParent­And­Item::Get­Parent­And­Item<\/code> method<\/a>. Once nice thing about the IParent­And­Item::Get­Parent­And­Item<\/code> method is that you can pass nullptr<\/code> for the things you aren’t interested in. <\/p>\n

Alternatively, if you want to peek inside and get the ITEMIDLIST_ABSOLUTE<\/code>, then you can use the IPersist­ID­List::Get­ID­List<\/code> method<\/a> to suck it out. We saw this a while back<\/a>, but I’ll repeat it here just so the information is all in one place. <\/p>\n

If you are willing to abandon Windows XP support, you can use the SH­Get­ID­List­From­Object<\/code> function<\/a> which knows how to do this. (It tries other things, too.) <\/p>\n

Okay, let’s take things out for a spin. We’ll get the normal display name for a shell item in four ways: <\/p>\n