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iosobjective-cnsuserdefaultsnskeyedarchivernskeyedunarchiver

Store Custom Objects in NSUserDefaults


I am trying to store a custom objects as follows, but I am getting an error.

// store data
NSMutableArray *archiveArray = [NSMutableArray arrayWithCapacity:pOrderElements.count];
for (id orderObject in pOrderElements) {
    NSData *personEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:orderObject];
    [archiveArray addObject:personEncodedObject];
}

NSUserDefaults *userData = [NSUserDefaults standardUserDefaults];
[userData setObject:archiveArray forKey:@"personDataArray"];


// retrive data
NSData *data = [userData objectForKey:@"personDataArray"];
// the following line throws an error
id retrieveData = [NSKeyedUnarchiver unarchiveObjectWithData:data];

here is my pOrderElements

(lldb) po pOrderElements
<__NSArrayM 0x174256b90>(
{
    category = 1;
    imagePath = "products/chicken-kabob.png";
    name = "Baked Chicken";
    price = "5.49";
}
)

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFArray bytes]: unrecognized selector sent to instance 0x174264f40'


Solution

  • You unarchive incorrect object. You store NSArray to NSUserDefaults

    NSArray * archiveArray = [userData objectForKey:@"personDataArray"];
    for (NSData *personEncodedObject in archiveArray) {
        id personObject = [NSKeyedUnarchiver unarchiveObjectWithData:personEncodedObject];
    }