Archiving a modified array - noNotRecognizeSelector exception

Question

I have a "doesNotRecognizeSelector" exception, and I suspect that perhaps my unarchiver returns an immutable array that is in the mutable variable. I'm right? How should I archive and archive correctly? (exception location is shown)

Thank!!!

NSMutableArray* arr;

- (void) write
{
         NSMutableData *data = [[NSMutableData alloc] init];
         NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];

 NSMutableArray *copy = [[NSMutableArray arrayWithArray:self.Arr] copy];
        [archiver encodeObject:copy forKey:@"Key"];
        [archiver finishEncoding];
        [data writeToFile:[Util DataPath] atomically:YES];
        [archiver release];
        [data release];
        [copyOfPaidPacks release];
}




-(NSMutableArray*) read
{
    NSString* DataPath = [Util FilePath];
    NSData *data = [[NSMutableData alloc] initWithContentsOfFile:DataPath];
    NSKeyedUnarchiver *unarchiver = nil;
    if (data != nil)
    {
            unarchiver = [[NSKeyedUnarchiver alloc]initForReadingWithData:data];

    if([self.Arr count] <= 0)
    {
        self.Arr = [unarchiver decodeObjectForKey:@"Key"];  
    }
}

[unarchiver finishDecoding];
[unarchiver release];
[data release];
    return self.arr
}

-(void)B
{
     [self write];
     NSMutableArray* SecondArr = [self read];
     [SecondArr sortUsingSelector:@selector(CompareDate:)]; - > `****THIS IS WHERE I GET THE EXCEPTION`
}

• Edit

Adding a comparison method:

- (NSComparisonResult)CompareDate:(T*)p
{
    NSComparisonResult result = [self.changeDate compare:p.changeDate];
    if(result == NSOrderedDescending)
        result = NSOrderedAscending;
    else if(result == NSOrderedAscending)
        result = NSOrderedDescending;

    if(result == NSOrderedSame)
    {
        result = [self CompareName:p];
    }

    return result;
}

Answer 1

NSKeyedUnarchiverreally returns immutable NSArray. If you really want to get NSMutableArray, you need to call -mutableCopyfor the return value from decodeObjectForKey:.

, . , , -read. sortedArrayUsingSelector: NSArray?

Answer 2

, , unarchiver ?

, ,

NSMutableArray *copy = [[NSMutableArray arrayWithArray:self.Arr] mutableCopy];

NSMutableArray *copy = [[NSMutableArray arrayWithArray:self.Arr] copy];

( , , ). , , , , Cocoa , ).

EDIT: NSKeyedArchiver iOS 5.0:

// this returns a mutable instance at runtime!
NSMutableArray* test0 = [NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:[NSMutableArray array]]];
// this returns an immutable instance at runtime!
NSArray* test1 = [NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:[NSArray array]]];

, mutableCopy, !

Answer 3

, (.. ) unarchive .

NSKeyedUnarchiver

- (Class)classForClassName:(NSString *)codedName
{
    Class theClass = [super classForClassName: codeName];

    if ([codeName isEqualToString: NSStringFromClass(NSArray.class))
    {
        theClass = NSMutableArray.class;
    }
    //... more here like NSDictionary
    return theClass;
}