numberOfPreviewItems(in:)
Returns the number of preview items to include in the preview navigation list.
Declaration
func numberOfPreviewItems(in controller: QLPreviewController) -> IntParameters
- controller:
The Quick Look preview controller that’s requesting the number of preview items.
Return Value
The number of items that the Quick Look preview controller should include in its preview navigation list.
Discussion
The system invokes this method to inform the preview controller of the number of preview items available.
If you push a Quick Look preview controller into view using a UINavigationController object that has a toolbar, the system automatically displays arrows in the toolbar to navigate among the items in the navigation list. If you’re not displaying a toolbar and want to provide your own method of switching among items, use the currentPreviewItemIndex property to indicate the item you want to display.
If you display a preview controller modally (full screen), the controller includes navigation arrows if there’s more than one item in the navigation list.