简单分配不适用于UIImage * / imageNamed

Question

UIImage* test = [UIImage imageNamed:@"test.png"];
self.image_in_controller = test;

Later in the code when image_in_controller is used, I get EXC_BAD_ACCESS.

I set a break point around the time of the assignment. The variable test is getting set just fine.. after the assignment to selfimage_in_controller, test is still okay, but image_in_controller points to 0x0 (not nil).

If I run the same code in the simulator it works fine (self.image_in_controller has a valid point address).

Any ideas?

Answer 1

Is the property image_in_controller a retained property? If not, you will have to explicitly take ownership of the image with a retain message. So one of either:

@property(retain) UIImage* image_in_controller;

or

self.image_in_controller = [test retain];

should exist. The EXC_BAD_ACCESS is often caused by using an object that's been destroyed. Also, test to make sure that test is not actually nil. You can do this with an assertion:

NSParameterAssert(test);

just after test is assigned. It will let you know if UIImage is not returning a valid object for some reason on the device.

Finally, 0x0 is the memory address of nil , so you will often see that in the debugger and can (for all intents and purposes) be considered the same as nil, Nil, NULL and 0.