I'm having problems unarchiving an NSMutableSet object in my iPhone (iOS 4.3) app.
I have a subview of UIImageView that contains an ivar of type NSMutableSet. I have defined the NSMutableSet in the header (and synthesized it in the implementation):
@interface MyView : UIImageView
{
NSMutableSet *group;
}
@property (nonatomic, retain) NSMutableSet *group;
The set contains references to zero or more objects of type MyView. Since group is an attribute of MyView, the references to non-nil group members (MyView objects) are circular.
I encode this view like so:
- (void) encodeWithCoder:(NSCoder *)aCoder
{
NSLog(@"Encoding group for %@ -- %@", self.imageFilename, self.group);
[aCoder encodeObject:self.group forKey:@"group"];
}
The NSLog shows a healthy group object being archived. But when I unencode, I get an NSException:
- (id) initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithFrame:CGRectZero];
self.group = [aDecoder decodeObjectForKey:@"group"]; // <- NSException here.
return self;
}
The first time I saw this bug, I got a fairly detailed error message: Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[NSCFSet count]: method sent to an uninitialized mutable set object'
However开发者_运维问答, when I reproduce the problem, I get a far less informative message: terminate called after throwing an instance of 'NSException'
The achive is created with this command:
[NSKeyedArchiver archiveRootObject:parentOfMyView toFile:myFilepath];
And opened with this one:
[NSKeyedUnarchiver unarchiveObjectWithFile:myFilepath];
Thanks for any help with this.
-- rich
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