NSDate ivar become <not an Objective-C object>?

问题

- (id)initWithCoder:(NSCoder *)aDecoder
{
   dueDate = [NSDate date];

}

- (void)viewDidLoad
{
    [super viewDidLoad];

    NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease];
    [formatter setDateStyle:NSDateFormatterShortStyle];
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    self.lbDueDate.text = [formatter stringFromDate:dueDate];
}

In init method I declared dueDate = [NSDate date]. But when I debug, at this line

    self.lbDueDate.text = [formatter stringFromDate:dueDate];

And Output: (NSDate *) dueDate = 0x0c497390 So what happend ?

回答1:

It means the object's been -dealloced (unless it is nil). So run with Zombies and message it more often -- after running the static analyzer and reviewing your code.

one problem in the source: dueDate = [NSDate date]; should be dueDate = [[NSDate date] copy];. another problem is that you don't call through the superclass' designated initializer in your implementation of -initWithCoder:.

来源：https://stackoverflow.com/questions/15049971/nsdate-ivar-become-not-an-objective-c-object