Errore durante il recupero dell'oggetto dalla proprietà dell'elemento dell'array - obiettivo-c, ios

Ho una semplice applicazione Cocoa, che analizza JSON e racchiude le informazioni di JSON nell'oggetto della classe Day.

Day.h.

#import <Foundation/Foundation.h>

@interface Day : NSObject

@property(retain, nonatomic) NSString *dateString;

@end

main.m

import <Foundation/Foundation.h>
import </Users/Admin/Documents/SimpleJsonParser/SBJSON.h>
#import "Day.h"

int main(int argc, const char * argv[])
{

@autoreleasepool {

// source json object
NSString *jsonSource = @"{"days":[{"dateString":"10 december"},{"dateString":"11 december"}]}";

SBJsonParser *jsonParser = [[SBJsonParser alloc] init];

NSError *error = nil;

NSDictionary *jsonObjects = [jsonParser objectWithString:jsonSource error:&error];

if(error != nil){
NSLog([error description]);
}

// array of days objects
NSArray *days = [jsonObjects objectForKey:@"days"];

// create empty array
NSMutableArray *daysSource = [[NSMutableArray array] retain];

for(int i = 0; i < [days count]; i++){

NSDictionary *day = [days objectAtIndex:i];

// get dateString
NSString *dateString = [day objectForKey:@"dateString"];

// create Day object
Day* dayObject = [[Day alloc] init];

dayObject.dateString = dateString;

NSLog(dayObject.dateString);

[daysSource addObject:day];
}

NSUInteger temp = [daysSource count];
NSLog(@"Temp is %lu", temp);

Day *myDay = [daysSource objectAtIndex:0];

NSString *dateStringTemp = myDay.dateString;
}
}

E quando eseguo questo codice, ottengo questo errore:

2012-12-11 14:09:50.867 SimpleJsonParser[577:303] -[__NSDictionaryM dateString]: unrecognized selector sent to instance 0x10010e4d0
2012-12-11 14:09:50.869 SimpleJsonParser[577:303] *** Terminating app due to uncaught exception "NSInvalidArgumentException", reason: "-[__NSDictionaryM dateString]: unrecognized selector sent to instance 0x10010e4d0"
*** First throw call stack:
(
0   CoreFoundation                      0x00007fff90a2e0a6 __exceptionPreprocess + 198
1   libobjc.A.dylib                     0x00007fff8c6713f0 objc_exception_throw + 43
2   CoreFoundation                      0x00007fff90ac46ea -[NSObject(NSObject) doesNotRecognizeSelector:] + 186
3   CoreFoundation                      0x00007fff90a1c5ce ___forwarding___ + 414
4   CoreFoundation                      0x00007fff90a1c3b8 _CF_forwarding_prep_0 + 232
5   SimpleJsonParser                    0x0000000100001700 main + 704
6   libdyld.dylib                       0x00007fff850b57e1 start + 0
7   ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminate called throwing an exception
(lldb)

Perché la proprietà "dateString" della classe Day salvata come NSDictionary?

risposte:

Stai aggiungendo il dictionary no all'array no Day oggetto.

Modificare:

[daysSource addObject:day];

a

[daysSource addObject:dayObject];

L'oggetto è tornato da [daysSource objectAtIndex:0] è un NSDictionary

NSDictionary *myDay = [daysSource objectAtIndex:0];

NSString *dateStringTemp = [myDay objectForKey:@"dateString"];

il giorno è un dizionario. Lo memorizzi in daySource e poi lo fai Day *myDay = [daysSource objectAtIndex:0];