xcode – 我正在获得21004作为状态值来回应苹果的沙盒服务器测试

#define SHARED_SECRET @"INSERT HERE YOUR ITUNESCONNECT SHARED SECRECT KEY FOR AUTORENEWABLE SUBCRIPTIONS RECEIPT VALIDATION"

-(void)checkReceipt {
// verifies receipt with Apple
NSError *jsonError = nil;
NSString *receiptBase64 = [NSString base64StringFromData:receiptData length:[receiptData length]];
NSLog(@"Receipt Base64: %@",receiptBase64);

NSData *jsonData = [NSJSONSerialization dataWithJSONObject:[NSDictionary dictionaryWithObjectsAndKeys:
                                                            receiptBase64,@"receipt-data",SHARED_SECRET,@"password",nil]
                                                   options:NSJSONWritingPrettyPrinted
                                                     error:&jsonError
                    ];
NSLog(@"%@",jsonData);
NSError * error=nil;
NSDictionary * parsedData = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&error];
NSLog(@"%@",parsedData);
NSLog(@"JSON: %@",[[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding]);
// URL for sandbox receipt validation; replace "sandbox" with "buy" in production or you will receive
// error codes 21006 or 21007
NSURL *requestURL = [NSURL URLWithString:@"https://sandbox.itunes.apple.com/verifyReceipt"];

NSMutableURLRequest *req = [[NSMutableURLRequest alloc] initWithURL:requestURL];
[req setHTTPMethod:@"POST"];
[req setHTTPBody:jsonData];
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:req delegate:self];
if(conn) {
    receivedData = [[NSMutableData alloc] init];
} else {
    completionBlock(NO,@"Cannot create connection");
}
}

有人可以帮我收到正确的收据验证吗？