My application crashed with the reason:
-[MyClassName copyWithZone:] unrecognized selector sent to instance
I have two classes. Let's say Class1 and Class2.
Class1 looks like:
@interface Class1 : NSObject {
NSString *imagemd5CheckSum;
UIImage *image;
NSData *fileChunkData;
}
@property (nonatomic, copy)NSString *imagemd5CheckSum;
@property (nonatomic, copy)UIImage *image;
@property (nonatomic, copy)NSData *fileChunkData;
@end
@implementation Class1
@synthesize image;
@synthesize fileChunkData;
@synthesize imagemd5CheckSum;
-(id) init{
[self setImage:nil];
[self setFileChunkData:nil];
[self setImagemd5CheckSum:@""];
return self;
}
-(void)dealloc{
[imagemd5CheckSum release];
[image release];
[fileChunkData release];
fileChunkData = nil;
imagemd5CheckSum = nil;
image = nil;
[super dealloc];
}
@end
**
Class2 looks like
**
#import "Class2.h"
@interface Class2 : NSObject {
Class1 *obj1;
Class1 *obj2;
Class1 *obj3;
}
@property (nonatomic, copy)Class1 *obj1;
@property (nonatomic, copy)Class1 *obj2;
@property (nonatomic, copy)Class1 *obj3;
@end
@implementation Class2
@synthesize obj1,obj2,obj3;
-(id) init{
[self setObj1:nil];
[self setObj2:nil];
[self setObj3:nil];
return self;
}
-(void)dealloc{
[obj1 release];
[obj2 release];
[obj3 release];
obj1 = nil;
obj2 = nil;
obj3 = nil;
[super dealloc];
}
@end
Class2 *class2 = [[Class2 alloc] init];
Class1 *class1 = [[Class1 alloc] init];
[class1 setImagemd5CheckSum:@"this is md5"];
[class1 setImage:myimage];
[class1 setFileChunkData:myData];
[class2 setObj1:class1]; // This line is crashed..
...
When I called [class2 setObj1:class1];
, the application crashed with reason:
-[Class1 copyWithZone:] unrecognized selector sent to instance
How can I fix this problem?
Your -setObj1:
method is declared as copy
, so it calls -copy
on your Class1
object. -copy
just calls -copyWithZone:nil
. So you either need to implement the NSCopying
protocol (which means implementing -copyWithZone:
), or change your property from copy
to retain
.