IOS開發之CFURLCreateStringByAddingPercentEscapes–URL 編碼

#define SINA_API_AUTHORIZE          @"https://api.weibo.com/oauth2/authorize"

#define SINA_APP_KEY                @"3456404324"

- (NSURL*)getOauthCodeUrl {                
//擷取auth_code or access_token；留給webview用

    //https://api.weibo.com/oauth2/authorize

    //https://api.weibo.com/oauth2/authorize?client_id=YOUR_CLIENT_ID&response_type=code&redirect_uri=YOUR_REGISTERED_REDIRECT_URI

     NSMutableDictionary *params = [NSMutableDictionary
dictionaryWithObjectsAndKeys:

 
SINA_APP_KEY,                   
@"client_id",       //申請的appkey

@"token",                       
@"response_type",   //access_token

 
@"http://hi.baidu.com/jt_one",   @"redirect_uri",   
//申請時的重新導向地址

 
@"mobile",                      
@"display",         //web頁面的顯示方式

                                        
nil];

NSURL *url = [self
generateURL:SINA_API_AUTHORIZE
params:params];    //參數是可變個數的

NSLog(@"url= %@",url);

    return url;

}

- (NSURL *)generateURL:(NSString *)baseURL params:(NSDictionary *)params {

if (params) {

NSMutableArray *pairs = [NSMutableArray
array];

for (NSString *key
in params.keyEnumerator) {

NSString *value = [params
objectForKey:key];

            //將要添加到URL的字串進行特殊處理，如果這些字串含有 &，
？ 這些特殊字元，用“%+ASCII” 代替

NSString *escaped_value = (NSString *)CFURLCreateStringByAddingPercentEscapes(

 
NULL,
/* allocator */

 
(CFStringRef)value,

 
NULL, /* charactersToLeaveUnescaped */

 
(CFStringRef)@"!*'();:@&=+$,/?%#[]",

 
 kCFStringEncodingUTF8);

                [pairs addObject:[NSString
stringWithFormat:@"%@=%@", key, value]];

[escaped_value
release];

}

NSString *query = [pairs
componentsJoinedByString:@"&"];

NSString *url = [NSString
stringWithFormat:@"%@?%@", baseURL, query];

return [NSURL
URLWithString:url];

}
else {

return [NSURL
URLWithString:baseURL];

}

}