- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.        //URL百分號編碼    //URL編碼會編碼&,問號和其他標點符號。    NSString *urlString=@"http://myhost.com?query=This is a question";    NSString *encoded=[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];    NSLog(@"--urlString--%@",urlString);    NSLog(@"--endcoded--%@",encoded);    }

2015-08-18 21:41:58.501 百分號編碼[730:74165] --urlString--http://myhost.com?query=This is a question2015-08-18 21:41:58.501 百分號編碼[730:74165] --endcoded--http://myhost.com?query=This%20is%20a%20question