将一个UIView上下文的位图内容复制到另一个UIView

Question

Basically what I want to do is copy the already rendered content (a PDF drawn into the UIView's graphics context using CGContextDrawPDFPage()) onto a similar UIView, without having to re render the PDF. The idea is, that I'd then be able to perform an animated transform on the UIView and later re render the PDF with more accuracy. For both UIViews I'm using a larger-than-screen CATiledLayer to make it easier to rerender the PDF once the user zooms in, if that makes any difference.

Any tips? I'm kind of lost here.

Answer 1

Assuming you have rendered a PDF page in a graphics context using code similar to the following

CGPDFDocumentRef document = CGPDFDocumentCreateWithURL (filename_url);
CGPDFPageRef page = CGPDFDocumentGetPage (document, pageNumber); 
CGContextDrawPDFPage (context, page); 
CGPDFDocumentRelease (document);

This code will save the contents of pdfView to a UIImage

UIGraphicsBeginImageContext(pdfView.bounds.size);
[pdfView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *pdfViewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();