Store custom objects in NSUserDefaults in iOS

Question

I want to store custom objects in NSUserDefaults. I read the Apple doc and know NSUserDefaults can store only property lists such as

NSArray, NSNumber, NSData, NSDate, NSDictionary and NSString.

If I want to store custom object, then I need to implement NSCoding protocol.

I need someone can clarify a little bit for the following class:

@interface MyDrawBlock : BlockInfo
{
    CGPoint _blockUpLeft;
    CAShapeLayer* _shapeLayer;
    int _blockColorFlag;
    int _strokeColorFlag;
}

I have CAShapeLayer* _shaperLayer in my class. How can I store MyDrawBlock in NSUserDefaults?

If I implement NSCoding protocol, then how I can store CAShapeLayer* _shapeLayer.

You can;t store a file in NSUserDefualts. NSUserDefaults is for storing simple keys/arrays. — Teja Nandamuri, Jan 11 '16 at 21:22
this is not duplicated. My object is different from the given answer. Please read my question carefully. — 1234, Jan 11 '16 at 21:33
This looks like an [X/Y problem](http://meta.stackexchange.com/questions/66377/what-is-the-xy-problem). Step back and tell us what you are trying to do, and why you think you need to do it that way. In general, if you're trying to encode a view object (And a CAShapeLayer is a view object for the purpose of this discussion) then you're doing something wrong. View objects are for showing content, not for saving state. There is probably a better/more appropriate way to accomplish what you are trying to accomplish. — Duncan C, Jan 11 '16 at 22:02

score 0 · Accepted Answer · edited May 23 '17 at 11:52

0

Try using NSKeyedArchiver and NSKeyedUnarchiver.

Here look at this answer for a similar question: https://stackoverflow.com/a/2315972/4160199

edited May 23 '17 at 11:52

Community

answered Jan 11 '16 at 21:24

quant24

Thanks for the quick replay, but my class contains CAShapeLayer* _shapeLayer – 1234 Jan 11 '16 at 21:27
No Problem, but I don't see why you wouldn't be able to encode CAShapeLayer. Just encode it as an object. – quant24 Jan 11 '16 at 21:43
Thanks, actually it works for CAShaperLayer – 1234 Jan 12 '16 at 00:04
@JoobLee, note that storing a shape layer in user defaults is a bad idea. (See my comment to your question) – Duncan C Jan 12 '16 at 13:29

1 Answers1