获取writeToFile：原子地：保存到的URL

Question

I'm saving some NSData with writeToFile:atomically: and then want to use that file very shortly afterwards. What is the easiest way to get the NSURL of the file I just saved?

Answer 1

[NSData writeToFile: atomically:] has a path parameter.

Just make the path parameter into a file URL and save that as an instance variable or property and you'll be all set.

Or even better, use [NSData writeToURL: atomically:] (ie convert your path into a URL to start with) and save that as a property or instance variable to be used later on.

You can convert a path into a file URL via [[NSURL alloc] initFileURLWithPath:] .

And lastly, the real answer to the question you're trying to ask is: no, you can not divine the path or URL from an arbitrary " NSData " object. You'll have to save that information separately or alongside your data in order to keep track of where it came from.