该操作无法完成。 （可可错误3840。）”（在字符16周围的对象中没有键值。）

Question

Below is my sample code

 project = @"Project";
      projectId=@"ProjectID";
      issue =@"Issue";
      issueId=@"IssueID";
      activity =@"Activity";
      activityId=@"ActivityID";
      comment =@"Comment";
      entryID = @"EntryID";
      NSMutableDictionary *entryUser = [[NSMutableDictionary alloc] init];
      [entryUser setObject:@"5" forKey:common_Id];
      [entryUser setObject:@"Divya Bharathi" forKey:common_Name];

       NSMutableDictionary *sdetails = [[NSMutableDictionary alloc] init];
       NSMutableArray *time_entry = [[NSMutableArray alloc] init];
    //  NSMutableArray

      //self.dataArray = [[NSMutableArray alloc] init];
      NSString *strHours,*wkDay;
      for(int i=0;i < [self.dataArray count] ;i++)
      {        
        NSDictionary *dataDic = [self.dataArray objectAtIndex:i];
       NSMutableDictionary *projectDic = [[NSMutableDictionary alloc] init];
      [projectDic setObject:[dataDic objectForKeyedSubscript:projectId] forKey:common_Id];
      [projectDic setObject:[dataDic objectForKeyedSubscript:project] forKey:common_Name];

      NSMutableDictionary *issueDic = [[NSMutableDictionary alloc] init];
      [issueDic setObject:[dataDic objectForKeyedSubscript:issueId] forKey:common_Id];

      NSMutableDictionary *activityDic = [[NSMutableDictionary alloc] init];
      [activityDic setObject:[dataDic objectForKeyedSubscript:activityId] forKey:common_Id];
      [activityDic setObject:[dataDic objectForKeyedSubscript:activity] forKey:common_Name];


            for (int j=0; j<7; j++) {
                  wkDay=@"";strHours =@"";
                  wkDay = self.wkDateArray[i];
                 strHours = [NSString stringWithFormat:@"%@",[dataDic objectForKeyedSubscript:wkDay]];
                  if(strHours.length)
                  {
                        [sdetails setObject:[dataDic objectForKeyedSubscript:entryID] forKey:common_Id];
                        [sdetails setObject:projectDic forKey:project];
                        [sdetails setObject:issueDic forKey:issue];
                        [sdetails setObject:entryUser forKey:currentUser];
                        [sdetails setObject:activityDic forKey:activity];
                        [sdetails setObject:strHours forKey:@"hours"];
                        [sdetails setObject:[dataDic objectForKeyedSubscript:comment] forKey:comment];
                        [sdetails setObject:wkDay forKey:@"spent_on"];
                        [time_entry addObject:sdetails];                        
                  }

                  }
      }

      NSMutableDictionary *results = [[NSMutableDictionary alloc] init];
      [results setObject:time_entry forKey:@"entries"];
      [results setObject:entryUser forKey:currentUser];
      [results setObject:@"2016-01-17" forKey:@"startday"];
      [results setObject:@"New" forKey:@"status"];
      [results setObject:@"0.0" forKey:@"total"];

      NSMutableDictionary *wktime = [[NSMutableDictionary alloc] init];
      [wktime setObject:results forKey:@"time"];


 NSString *jsonStr = [NSString stringWithFormat:@"%@",wktime];
      NSError *jsonError;
      NSData *requestData = [jsonStr dataUsingEncoding:NSUTF8StringEncoding];

       NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:requestData options:NSJSONReadingMutableContainers error:&jsonError];

      NSLog(@"Json Data : %@",jsonData);
      NSLog(@"Error Values: %@",jsonError);

Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn't be completed. (Cocoa error 3840.)" (No value for key in object around character 16.) UserInfo=0x7feb58f21b90 {NSDebugDescription=No value for key in object around character 16.}

Answer 1

As Avi pointed out,

  NSString *jsonStr = [NSString stringWithFormat:@"%@",wktime];
  NSData *requestData = [jsonStr dataUsingEncoding:NSUTF8StringEncoding];

   NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:requestData options:NSJSONReadingMutableContainers error:nil];

you have created a string and converted it into NSData , but later trying to use the NSJSON API to convert it into a dictionary, which will fail since the original string isnt json encoded.

You should just convert the dict into Data using the NSJSON API and just read back, although its use wont make much sense till you tell the context.

  NSData *requestData = [NSJSONSerialization dataWithJSONObject: wktime options:NSJSONWritingPrettyPrinted error:nil];
   NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:requestData options:NSJSONReadingMutableContainers error:nil];

If you are trying to do a web request, i would suggest reading AFNetworking docs, that API is well built and can help a lot for web requests.