ios potential leak how to solve?

I've analyzed my project: and this is the result:

what means an开发者_StackOverflow中文版d how can I solve this?

You should release pdfURL after you have used it to create pdf.

Try...

CGPDFDocumentRef pdf = CGPDFDocumentCreateWithURL(pdfURL);
CFRelease(pdfURL);

It looks like you might want to familiarise yourself with the Memory Management Programming Guide for Core Foundation, specifically the ownership policy.

In short, you have to CFRelease() the pdfURL object. :-)