Designates an interface that allows a registered file viewer to be notified when it must show or print a file. The shell calls this interface when the user selects the Quick View command from a file's context menu and the file is a type that the file viewer recognizes. The IFileViewer interface has the following member functions:
Methods in Vtable Order
| IUnknown Methods | Description |
| QueryInterface | Returns pointers to supported interfaces. |
| AddRef | Increments reference count. |
| Release | Decrements reference count. |
| IFileViewer Methods | Description |
| PrintTo | Prints a file. |
| Show | Displays a file. |
| ShowInitialize | Prepares to display a file. |