NSString *encodedString = (NSString *)
CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(CFStringRef)self.url,
(CFStringRef)@"!$&'()*+,-./:;=?@_~%#[]",
NULL,
kCFStringEncodingUTF8));
NSLog(@"转码url:%@", encodedString);