Xcode-从服务器（例如time.is）获取当前日期和时间，并将其转换为NSDate

Question

i don't want to get the current date from the users device, because the user can edit the date.

i would like to get the current date and time from a server like time.apple.com or time.is and then convert it to an NSDate. How?

Answer 1

You can first get the date in the form of a string by hitting the url (if the webservice is giving it as a string). And then using date formatter you could make the string into an NSDate .

For instance:

NSURL *url = [NSURL URLWithString:@"http://yourtimeurl"];
NSString *str = [[NSString alloc] initWithContentsOfURL:url usedEncoding:Nil error:Nil];

assume you are getting the date in the format dd-MM-yyyy, then

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat =@"dd-MM-yyyy";
NSDate *date = [dateFormatter dateFromString:str];

But most probably when you hit your url, you might get some data structure like a json which you would have to parse. And most probably the date wouldn't be returned in the above format. But now you know how to go forward. Make the appropriate changes.

Also initWithContentsOfURL: is a synchronous call. It's recommended that you use a NSURLConnection for this and make asynch call to your webservice.

This might be useful: http://www.earthtools.org/webservices.htm#timezone --xmlresponse
http://www.timeapi.org/utc/now --string