Cannot parsing Json to NSDictionary

问题:

I have a WebService, which give me the fallowing Json-String back:

"{\"password\" : \"1234\",  \"user\" : \"andreas\"}" 

I call the webservice and try to parse the returned data like:

[NSURLConnection sendAsynchronousRequest: request                                    queue: queue                        completionHandler: ^(NSURLResponse *response, NSData *data, NSError *error) {           if (error || !data) {            // Handle the error         } else {            // Handle the success            NSError *errorJson = nil;            NSDictionary *responseDict = [NSJSONSerialization JSONObjectWithData: data options: NSJSONReadingMutableContainers error: &errorJson];            NSString *usr = [responseDict objectForKey:@"user"];         }    }  ]; 

But the resulting NSDictionary looks like:

What has the effect, that I cannot get the values - for example user. Can someone help me, what I am doing wrong? - Thank you.

回答1:

From the debugger screenshot is seems that the server is (for whatever reason) returning "nested JSON": responseDict[@"d"] is a string containing JSON data again, so you have to apply NSJSONSerialization twice:

NSError *errorJson = nil; NSDictionary *responseDict = [NSJSONSerialization JSONObjectWithData: data options:0 error: &errorJson]; NSData *innerJson = [responseDict[@"d"] dataUsingEncoding:NSUTF8StringEncoding]; NSMutableDictionary *innerObject = [NSJSONSerialization JSONObjectWithData:innerJson options:NSJSONReadingMutableContainers error:&errorJson]; NSString *usr = [innerObject objectForKey:@"user"]; 

If you have the option, a better solution would be to fix the web service to return proper JSON data.

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