cannot read a readonly property, compiler complains.

Question

Hi,

I'm new to Objective C, but have extensive C++ experience.

I have a member variable called bOn, which I have declared as a readonly property. I then synthesize it.

However, the compiler won't let me read it, saying "Instance Variable 'bOn' is declared protected". I would understand this error if I had not synthesized.

Here are my snippets:

@interface Button : NSObject

{

    . . .
    BOOL bOn;
}

@property (nonatomic, readonly) BOOL bOn;

And where I use it:

 -(void) updateForButtonLeft:(Button *)butLeft Right:(Button *)butRight

{

    BOOL bLeft = butLeft->bOn;
    . . .

So what else am I forgetting to do?

Thanks,

Dave.

Answer 1

butLeft->bOn; is direct instance variable access and under all but very rare circumstances, is a really bad idea.

What you're looking for is:

BOOL bLeft = butLeft.b0n;

Or

BOOL bLeft = [butLeft b0n];