[xcode+object-c] URL encode－viaLondon的部落格

參考網頁：
https://madebymany.com/blog/url-encoding-an-nsstri...
http://stackoverflow.com/questions/25693758/ios-ns...
http://stackoverflow.com/questions/21829489/what-i...

起初，想把我程式內的URL改成percent encoding format。
例如：http://www.test.com/example?param=/wEF+rfc==
換成：http://www.test.com/example?param=%2FwEF%2Brfc%3D%3D

但使用了以下兩個functions得出來的結果都不是我要的。

stringByAddingPercentEscapesUsingEncoding
will convert the Unicode character to the percent escape format.

stringByReplacingPercentEscapesUsingEncoding
will do the opposite, convert the percent escape to the Unicode.

原來這兩個functions遇到以下符號是不作用的。

(

)

;

[

]

%21

%27

%28

%29

%2A

%2B

%2C

%2F

%3A

%3B

%3D

%3F

%40

%23

%24

%26

%5B

%5D

Examples:

NSString *rawText = @"+886, Taipei, Taiwan";
NSString *encodedText = [rawText stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"Encoded text: %@", encodedText);
NSString *decodedText = [encodedText stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"Original text: %@", decodedText);

Here’s the output:

Encoded text: +886,%20Taipei,%20Taiwan
Original text: +886, Taipei, Taiwan

需要改成以下寫法：

- (NSString *)urlEncode:(NSString *)str {
return (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)str, NULL, CFSTR("!*'();:@&=+$,/?%#[]"), kCFStringEncodingUTF8));
}

NSString *baseURL = @"http://www.test.com/example";
NSString *paramsString = @"/wEF+rfc==";
NSString *resultingURLString = [NSString stringWithFormat:@"%@?param=%@", baseURL, [self urlEncode:paramsString]];

Here’s the output:

http://www.test.com/example?param=%2FwEF%2Brfc%3D%...