UIApplication openUrl not working with formatted NSString

问题

I have the following code to open google maps:

NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps?q=%@, Anchorage, AK",addressString];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]];

But it doesn't work and there is no error. It just doesn't open.

回答1:

URLWithString requires a percent-escaped string. Your sample url contains spaces which results in a nil NSURL being created. Additionally, the addressString may also contain characters that need to be escaped. Try percent-escaping the url string first:

NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps?q=%@, Anchorage, AK",addressString];
NSString *escaped = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:escaped]];  

回答2:

Need to escape the urlString , else [NSURL URLWithString:urlString] will return nill.

NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps?q=%@, Anchorage, AK",addressString];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] ]];

来源：https://stackoverflow.com/questions/2534888/uiapplication-openurl-not-working-with-formatted-nsstring