On Tue, Aug 17, 2010 at 4:03 PM, James Miller <jmiller3...@gmail.com> wrote:
> Hello. > > I'm a little new to Objective-C / Cocoa so please don't shoot me, but I've > been looking around for a few hours and can't seem to figure out what I'm > doing wrong on my own and could use a second/third/fourth set of eyes. > > I have NSTimer that runs several times a second against an NSString called > level, which is 190 characters long and previously initialized from: > > // NSString *level = [[NSString alloc] > // > initWithContentsOfFile:path > // > encoding:NSUTF8StringEncoding > // error:&error]; > > > During the timer call, the level NSString is modified by the following line > of code: > > level=[level stringByReplacingCharactersInRange:NSMakeRange(5,1) > withString:@" "]; > > This operation appears to succeed as I print it via NSLog and it looks fine > and the length checks out, but the next time through the NSTimer I get a bus > error and the application dies. > > If I comment out the line above, the code continues to run fine. Am I doing > something wrong in terms of how I am using this method or assigning it back > to the NSString? > > > The result of the stringByReplacingCharactersInRange: method call is not retained between NSTimer callback invocations. It will leak memory, but as a quick test of that diagnosis, replace this line: level=[level stringByReplacingCharactersInRange:NSMakeRange(5,1) withString:@" "] with level=[[level stringByReplacingCharactersInRange:NSMakeRange(5,1) withString:@" "] retain]; If that works, as a permanent fix declare the variable "level" a property of the class and use synthesized accessors to assign the value of "level", which will retain/release it correctly: #1: add to your header file: @property(readwrite, retain) NSString *level; #2: you should already have the variable defined in your header: NSString *level; #3: Add to your .m file @synthesize level; #4: and replace your stringByReplacingCharactersInRange invocation line with this: self.level=[self.level stringByReplacingCharactersInRange:NSMakeRange(5,1) withString:@" "]; or if you prefer this style [self setLevel:[ [self level] stringByReplacingCharactersInRange:NSMakeRange(5,1) withString:@" "]]; - Allen _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
