# init(_:mediaBox:_:) Creates a URL-based PDF graphics context. ``` init?(_ url: CFURL, mediaBox: UnsafePointer?, _ auxiliaryInfo: CFDictionary?) ``` ## Parameters `url` A Core Foundation URL that specifies where you want to place the resulting PDF file. `mediaBox` A rectangle that specifies the bounds of the PDF. The origin of the rectangle should typically be `(0,0)`. The `CGPDFContextCreateWithURL` function uses this rectangle as the default page media bounding box. If you pass `NULL`, `CGPDFContextCreateWithURL` uses a default page size of 8.5 by 11 inches (612 by 792 points). `auxiliaryInfo` A dictionary that specifies any additional information to be used by the PDF context when generating the PDF file, or `NULL`. The dictionary is retained by the new context, so on return you may safely release it. ## Return Value A new PDF context, or `NULL` if a context could not be created. In Objective-C, you’re responsible for releasing this object using [`CGContextRelease`](/documentation/CoreGraphics/CGContextRelease). ## Discussion When you call this function, Core Graphics creates a PDF drawing environment—that is, a graphics context—to your specifications. When you draw into the resulting context, Core Graphics renders your drawing as a series of PDF drawing commands stored in the specified location. --- 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)