# QLPreviewRequestCreatePDFContext(_:_:_:_:) Creates a PDF context suitable to draw a multi-page preview. ``` func QLPreviewRequestCreatePDFContext(_ preview: QLPreviewRequest!, _ mediaBox: UnsafePointer!, _ auxiliaryInfo: CFDictionary!, _ properties: CFDictionary!) -> Unmanaged! ``` ## Parameters `preview` The preview request object. `mediaBox` A pointer to the media box of the context. A media box is a rectangle that defines the size and location of the PDF page. The origin of the rectangle should typically be (0,0). If you pass NULL, Quartz uses a default page size of 8.5 by 11 inches (612 by 792 points). For information see the description for . `auxiliaryInfo` A dictionary containing PDF auxiliary information. See the description of the auxiliary dictionary keys in for more information about the keys and values of this dictionary. `properties` A dictionary containing additional properties for the preview response. For information on acceptable keys and values, see `Preview Properties`. ## Return Value A reference to a Core Graphics context object that is used to display a PDF version of the preview. You should explicitly release this object when it is no longer needed. ## Discussion Be sure to bracket each PDF page written to the context with and calls. After calling this function, you should flush the context with [`QLPreviewRequestFlushContext(_:_:)`](/documentation/QuickLook/QLPreviewRequestFlushContext(_:_:)). ### Special Considerations Thread-safety: This function should be called in the same thread as the preview request is made in; generally, this is the same thread in which the `GeneratePreviewForURL` callback was invoked. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)