CGPDFDocumentGetPage

CGPDFDocumentGetPage is a function provided by the Core Graphics framework in macOS and iOS. It is used to retrieve a specific page from a PDF document. This function is part of the Quartz 2D API, which is a two-dimensional drawing engine used for rendering vector graphics and text.

The function takes two parameters: a reference to a CGPDFDocument object and an integer representing the page number. The page number is 1-based, meaning the first page of the document is page number 1. The function returns a CGPDFPage object, which represents the specified page of the PDF document.

If the specified page number is less than 1 or greater than the number of pages in the document, the function returns NULL. This function is useful for applications that need to render or manipulate specific pages of a PDF document.

Here is a simple example of how to use CGPDFDocumentGetPage:

```c

CGPDFDocumentRef pdfDocument = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfURL);

CGPDFPageRef pdfPage = CGPDFDocumentGetPage(pdfDocument, 1);

if (pdfPage != NULL) {

// Use the pdfPage object as needed

}

CGPDFDocumentRelease(pdfDocument);

```

In this example, a PDF document is created from a URL, and the first page of the document is retrieved using CGPDFDocumentGetPage. The retrieved page is then used as needed. Finally, the PDF document is released to free up resources.