iPhone - 苹果因发布 NSMutableArray 而崩溃

Question

This is my code using NSMutableArray.

- (void) put:(NSString *)key value:(NSString *)value
{
    Element *element = [[[Element alloc] initWith:key strValue:value] autorelease];
    if (self.map) {
        [map addObject:element];
    }
    else {
        map = [NSMutableArray arrayWithObject:element];
    }
}

-(void)dealloc
{
    if (map) {
            [map release];
    }

    [super dealloc];
}

My apple crashes at line:[map release];

What's wrong in my code?

I tried releasing 'map' as follow.

- (void) put:(NSString *)key value:(NSString *)value
{
    Element *element = [[[Element alloc] initWith:key strValue:value] autorelease];
    if (self.map) {
        [map addObject:element];
    }
    else {
        map = [NSMutableArray arrayWithObject:element];
        [map release]
    }

}

Then the apple does not crash. How solve this problem?

Answer 1

The arrayWithObject: method returns an autoreleased object; you need to either retain the array:

map = [[NSMutableArray arrayWithObject:element] retain];

or use the initWithObject: method:

map = [[NSMutableArray alloc] initWithObject:element];

Answer 2

If map is a retained/copied property do self.map=... to retain it. [NSMutableArray arrayWithObject:element] returns an autoreleased object that needs to be retained.

Answer 3

You are using the convenience initializer arrayWithObject , which has an implicit autorelease . You can't release an autoreleased object.