在 iOS 程序訪問 HTTP 資源時需要對 URL 進行 Encode,比如像拼出來的 http://unmi.cc?p1=%+&sd f&p2=中文,其中的中文、特殊符號&%和空格都必須進行轉譯才能正確訪問。現在以"?!@#$^&%*+,:;='\"`<>()[]{}/\\| "字符串爲例子,用stringByAddingPercentEncodingWithAllowedCharacters取代CFURLCreateStringByAddingPercentEscapes
原字符串爲:
<span style="font-family:SimSun;font-size:14px;">NSString *url = @"ertehtt""p://xxdsdscrg?!@#$^&%*+,:;='\"`<>()[]{}/\\| ";</span>
CFURLCreateStringByAddingPercentEscapes方法爲:
<span style="font-family:SimSun;font-size:14px;"> CFStringRef encodedCFString = CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(__bridge CFStringRef) url,
nil,
CFSTR("?!@#$^&%*+,:;='\"`<>()[]{}/\\| "),
kCFStringEncodingUTF8);
NSString *encodedString1 = [[NSString alloc] initWithString:(__bridge_transfer NSString*) encodedCFString];</span>
stringByAddingPercentEncodingWithAllowedCharacters方法爲:
NSString *charactersToEscape = @"?!@#$^&%*+,:;='\"`<>()[]{}/\\| ";
NSCharacterSet *allowedCharacters = [[NSCharacterSet characterSetWithCharactersInString:charactersToEscape] invertedSet];
NSString *encodedUrl = [url stringByAddingPercentEncodingWithAllowedCharacters:allowedCharacters];
NSLog(@"\n%@\n%@",encodedUrl,encodedString1);
之後獲得的字符串爲一致的。