Re: [NSMutableDictionary setObject:forKey:] problem
Re: [NSMutableDictionary setObject:forKey:] problem
- Subject: Re: [NSMutableDictionary setObject:forKey:] problem
- From: m <email@hidden>
- Date: Wed, 19 Oct 2005 15:15:22 -0700
On Oct 19, 2005, at 2:49 PM, Joachim wrote:
2) Why does [iPhotoAlbumDict respondsToSelector:@selector
(objectForKey)] always return false? ([iPhotoAlbumDict class] returns
NSCFDictionary.)
if (true || [iPhotoAlbumDict respondsToSelector:@selector
(objectForKey)]) {
// The second half of the above expression always
returns false,
// even though iPhotoAlbumDict DOES respond to the
message below
"@selector(objectForKey)" should be "@selector(objectForKey:)" (note
the colon; this is a common error beginners make)
1) What's wrong with my code [below]? Why isn't the NSDictionary
object added with the setObject:forKey: call?
// Initialise albumDict ivar
if (albumDict)
[albumDict release];
[albumDict initWithCapacity:[iPhotoAlbums count]];
You're not creating albumDict anywhere. So albumDict is probably nil.
3) Am I handling memory correctly in my code? No leaks etc? I'm
still struggling to understand how Objective-C memory management
works.
I haven't looked over your code carefully, but when you add an object
to a dictionary (or any container), the dictionary (or container)
retains it (increments the reference count by one). Since your object
is created using alloc+init, its being created with its reference
count already at 1. So you need either to release your object after
adding it to your dictionary, or (what I usually do) autorelease it
when creating it.
Finally, does NSDictionary read the whole file into memory in the
initWithContentsOfFile: call or does it just scan the file later at
the given entry levels I specify in my code? The AlbumData.xml file
can get quite big, but I don't want to use NSXMLParser as it
involves way too much code.
Dunno. I wouldn't worry about it until there's evidence that it's a
problem (i.e. you might be prematurely optimizing).
_murat
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden