转：http://blog.csdn.net/kesalin/article/details/6678939
[iOS]iOS 中的 url 编码问题
NSString 的 stringByAddingPercentEscapesUsingEncoding 可以对 url 参数进行编码，但是有点小问题，不会对所有需要编码的字符都编码。我们可以通过 CFStringRef 的
CFURLCreateStringByAddingPercentEscapes 函数来封装这个功能。代码如下：
- - (NSString *)encodeToPercentEscapeString: (NSString *) input
- {
- // Encode all the reserved characters, per RFC 3986
- // (<http://www.ietf.org/rfc/rfc3986.txt>)
- NSString *outputStr = (NSString *)
- CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
- (CFStringRef)input,
- NULL,
- (CFStringRef)@"!*'();:@&=+$,/?%#[]",
- kCFStringEncodingUTF8);
- return outputStr;
- }
- - (NSString *)decodeFromPercentEscapeString: (NSString *) input
- {
- NSMutableString *outputStr = [NSMutableString stringWithString:input];
- [outputStr replaceOccurrencesOfString:@"+"
- withString:@" "
- options:NSLiteralSearch
- range:NSMakeRange(0, [outputStr length])];
- return [outputStr stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
- }
测试代码：
- NSString * testUrl = @"http://search.google.com?keywords=($# it's {a*123})00!*'();:@&=+$,/?%#[]";
- NSLog(@"original: %@", testUrl);
- NSString * encodeStr = [self encodeToPercentEscapeString:testUrl];
- NSLog(@"encoded: %@", encodeStr);
- NSString * encodeStr2 = [testUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
- NSLog(@"encoded2:%@", encodeStr2);
- NSString * decodeStr = [self decodeFromPercentEscapeString:encodeStr];
- NSLog(@"decoded: %@", decodeStr);
结果如下：
- >> original: http://search.google.com?keywords=($# it's {a*123})00!*'();:@&=+$,/?%#[]
- >> encoded: http%3A%2F%2Fsearch.google.com%3Fkeywords%3D%28%24%23%20it%27s%20%7Ba%2A123%7D%2900%21%2A%27%28%29%3B%3A%40%26%3D%2B%24%2C%2F%3F%25%23%5B%5D
- >> encoded2: http://search.google.com?keywords=($%23%20it's%20%7Ba*123%7D)00!*'();:@&=+$,/?%25%23%5B%5D
- >> decoded: http://search.google.com?keywords=($# it's {a*123})00!*'();:@&=+$,/?%#[]
