Re: Problem when archiving data: [_NSViewGState encodeWithCoder:] unrecognized selector
Re: Problem when archiving data: [_NSViewGState encodeWithCoder:] unrecognized selector
- Subject: Re: Problem when archiving data: [_NSViewGState encodeWithCoder:] unrecognized selector
- From: "Ken Ferry" <email@hidden>
- Date: Fri, 25 Jul 2008 21:52:32 -0700
On Fri, Jul 25, 2008 at 9:33 PM, Ken Ferry <email@hidden> wrote:
>> [coder encodeValueOfObjCType:@encode(NSNumber *) at:&magnitude];
>
> This isn't encoding the number object, this is encoding the pointer to
> the number object. When you get it out of the archive, you get the
> same pointer as you put in, but that pointer points to some random bit
> of memory in your app, not the number.
I'm sorry, this is wrong. Guess I shouldn't have replied so quickly
on reading this. :-) The object part ought to work.
You do have a line where you try to decode in encodeWithCoder where
you want to encode, and is the points property a C-array of points?
That is going to behave as I suggested. You're just encoding a
pointer, not the points themselves.
What Kyle said also applies.
-Ken
>
> Use [coder encodeObject:] to encode objects.
>
> Also, you're probably also better off using NSKeyedArchiver than
> NSArchiver, and using encodePoint:forKey:, encodeObject:forKey:, etc.
> The non-keyed archiver is not formally deprecated, but it shouldn't
> really be used in new code. Newer Cocoa classes cannot generally be
> encoded with the non-keyed archiver, and older classes do not
> necessarily encode all of their data when written to a non-keyed
> archive. Every time you encode something new in an encodeWithCoder:
> method to a non-keyed archiver, it breaks the ability of older
> versions of the class to read the archiver.
>
> -Ken
>
> On Fri, Jul 25, 2008 at 6:59 PM, Kyle Sluder
> <email@hidden> wrote:
>> On Fri, Jul 25, 2008 at 6:29 PM, JArod Wen <email@hidden> wrote:
>>> Since I didn't find any object in the data to be written has the type of
>>> NSViewGState, I am really confused about this error. Anyone can give me any
>>> suggestions?
>>
>> This is usually a case of failing to retain an object you own. If it
>> gets deallocated underneath your feet, an object of a different class
>> may wind up in the same place in memory, but your old pointers don't
>> know that. Often, because of the way the compiler has generated your
>> code, it's consistently an object of a certain but completely
>> unrelated class.
>>
>> --Kyle Sluder
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