Saving NSRect to NSUserDefaults

Question

Currently I'm trying to save an NSRect to my user defaults. Right now I'm using a NSValue to wrap it as an object then save it into the user defaults as an object with the following code

[userDefaults setObject:[NSValue valueWithRect:rect forKey:@"Key"]];

However, when I run it, I get an error that says [NSUserDefaults setObject:forKey:]: Attempt to insert non-property value 'NSRect: {{0, 0}, {50, 50}}' of class 'NSConcreteValue'.

Does anyone know how I can fix this? Thanks.

Missing brackets have nothing to do with this problem, your answer is on another SO thread which I'm linking. You will have to take additional steps to save your NSRect objects, I'm afraid - http://stackoverflow.com/questions/471830/why-nsuserdefaults-failed-to-save-nsmutabledictionary-in-iphone-sdk. — Perception, Oct 11 '11 at 13:49
Thanks for the link. I totally forgot about how NSUserDefaults only support a certain amount of objects. — TheAmateurProgrammer, Oct 11 '11 at 13:54

Mundi · Answer 1 · 2018-01-07T18:22:21.080

55

Here is a much simpler solution, using NSString:

// store:
[[NSUserDefaults standardUserDefaults] 
   setValue:NSStringFromCGRect(frame) forKey:@"frame"];

// retrieve:
CGRect frame = CGRectFromString(
   [[NSUserDefaults standardUserDefaults] stringForKey:@"frame"]);

Swift 4

// store
UserDefaults.standard.set(NSStringFromCGRect(rect), forKey: "frame")

// retrieve
if let s = UserDefaults.standard.string(forKey: "frame") {
   let frame = CGRectFromString(s)
}

edited Jan 07 '18 at 18:22

answered Oct 11 '11 at 14:06

Mundi

79,884
17
117
140

4

+1 I do like simple, OP just needs to use `NSStringFromRect` and `NSRectFromString`. – Joe Oct 11 '11 at 14:14

score 14 · Accepted Answer · answered Oct 11 '11 at 13:50

NSValue is not supported by the user defaults.

The value parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary. For NSArray and NSDictionary objects, their contents must be property list objects.

You need to archive the value into data then unarchive it when you access it.

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSRect rect = { 0, 0, 10, 20 };
NSValue *value = [NSValue valueWithRect:rect];

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:value];
[userDefaults setObject:data forKey:@"key"];
[userDefaults synchronize];

data = [userDefaults objectForKey:@"key"];
NSValue *unarchived = [NSKeyedUnarchiver unarchiveObjectWithData:data];
NSLog(@"%@", unarchived);

Saving NSRect to NSUserDefaults

2 Answers2

Swift 4