[Mono-osx] Memory Leak ?

[Matthew Hazlett]

When I try this:

                 t = NSTimer.CreateRepeatingScheduledTimer(1,delegate {
                     txtClock.StringValue = DateTime.Now.ToLongTimeString();
                 });


I get this error:

    Unhandled Exception: System.NullReferenceException: Object reference
    not set to an instance of an object
       at UglyClock.MainWindowController.<AwakeFromNib>m__0 () [0x00000]
    in <filename unknown>:0
       at MonoMac.Foundation.NSActionDispatcher.Apply () [0x00000] in
    <filename unknown>:0
       at (wrapper native-to-managed)
    object:[MonoMac.Foundation.NSActionDispatcher:Void Apply()]
    (MonoMac.Foundation.NSObject,MonoMac.ObjCRuntime.Selector)
       at (wrapper managed-to-native)
    MonoMac.AppKit.NSApplication:NSApplicationMain (int,string[])
       at MonoMac.AppKit.NSApplication.Main (System.String[] args)
    [0x00000] in <filename unknown>:0
       at UglyClock.MainClass.Main (System.String[] args) [0x00000] in
    <filename unknown>:0


My code was working, so I know the objects are all wired correctly. 
Humm, seems it can't find txtClock to update this way.  If I change the 
code to this it works great (So, I know the delegate is working):

             t = NSTimer.CreateRepeatingScheduledTimer(1,delegate {
                 Console.WriteLine(DateTime.Now.ToLongTimeString());
                 //txtClock.StringValue = DateTime.Now.ToLongTimeString();
             });

You know what could be wrong, sorry I'm a total noob, this is my 3rd day 
trying to use this.

> 	hazlema <mailto:hazlema at gmail.com>
> January 9, 2011 4:51 PM
>
>
> Ahh, ok. Thanks
> ------------------------------------------------------------------------
>
> 	kjpou <mailto:kjpou at pt.lu>
> January 9, 2011 3:33 PM
>
>
> Mathew
>
> It is not a memory leak.
>
> What you have to do is use a NSTimer.
>
> NSTimer t;
>
>             t = NSTimer.CreateRepeatingScheduledTimer(1,delegate {
>                  txtClock.StringValue = DateTime.Now.ToLongTimeString();
>             });
>
>
> When you use a .net timer it runs outside NSApplication loop.  The 
> NSTimer will run within the application loop allowing Cocoa to update 
> the field value correctly.
>
> I plan on writing an article about that in a couple of days.
>
>
> ------------------------------------------------------------------------
>
> 	Matthew Hazlett <mailto:hazlema at gmail.com>
> January 9, 2011 1:52 PM
>
>
>
> I made a terribly simple application, on the MainWindow I put a label 
> then in the code I had it update the label every 1000 of a second.
>
>         ...
>        Timer t = new Timer(1000);
>         ...
>
>         public override void AwakeFromNib ()
>         {
>             base.AwakeFromNib ();
>
>             t.Elapsed += delegate {
>                 txtClock.StringValue = DateTime.Now.ToLongTimeString();
>             };
>
>             t.Start();
>         }
>
> But it keeps throwing warning errors at me for every tick, what am I 
> missing and how do I fix it?
> /2011-01-09 13:47:30.563 UglyClock[79395:7103] *** 
> __NSAutoreleaseNoPool(): Object 0x540f80 of class NSCFString 
> autoreleased with no pool in place - just leaking/
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.ximian.com/pipermail/mono-osx/attachments/20110109/c5bc8238/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: postbox-contact.jpg
Type: image/jpeg
Size: 1525 bytes
Desc: not available
Url : http://lists.ximian.com/pipermail/mono-osx/attachments/20110109/c5bc8238/attachment-0002.jpg 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: compose-unknown-contact.jpg
Type: image/jpeg
Size: 1421 bytes
Desc: not available
Url : http://lists.ximian.com/pipermail/mono-osx/attachments/20110109/c5bc8238/attachment-0003.jpg