Question

I am using the MBProgressHUB, with variations on the code found here.

Some things about my code:

• The code is in my App Delegate
• A number of other classes call it
• I’m using it with asynchronous NSURLConnection
• I do not declare it: @property (nonatomic, retain) MBProgressHUD *HUD;
• I do not: @synthesize HUD;
• (and of course I do not release it in my dealloc)

I use it as follows:

- (void)setSearchingMode:(BOOL)isSearching {
    // when network action, toggle network indicator and activity indicator
    if (isSearching) {
        [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
        
        UIWindow *theWindow = [UIApplication sharedApplication].keyWindow;
        HUD = [[MBProgressHUD alloc] initWithWindow:theWindow];
        [theWindow addSubview:HUD];
        
        //HUD.labelText = @"Connecting";
        [HUD show:YES];
    } else {
        [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
        
        [HUD hide:YES];
        [HUD removeFromSuperview];
        [HUD release];
    }
}

- (void)setSearchingText:(NSString *)whatToSay {
    HUD.labelText = whatToSay;
}

I am fairly sure that the code is causing a memory management problem somewhere. In my crash log, I get:

Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000c

0 libobjc.A.dylib 0x000027d8 objc_msgSend + 16
1 My 0x00003120 -[MyAppDelegate setSearchingMode:] (MyAppDelegate.m:363)
2 My 0x00003458 -[MyAppDelegate connectionDidFinishLoading:] (MyAppDelegate.m:341)
3 Foundation 0x00032896 -[NSURLConnection(NSURLConnectionReallyInternal) sendDidFinishLoading] + 62
4 Foundation 0x00032818 _NSURLConnectionDidFinishLoading + 72

in connectionDidFinishLoading I call:

[self setSearchingMode:NO];

I tried to do it by making property accessors for HUD, but was not able to get around the line "[MBProgressHUD alloc] initWithWindow" – and I don’t want to keep on alloc’ing an ivar!

Thanks, if anyone can point me in a better direction here..

Answer 1

If you happen to end up with the sequence of:

[self setSearchingMode:YES];
[self setSearchingMode:NO];
[self setSearchingMode:NO];

That code will crash as described because of the dangling reference to HUD. When you do [HUD release];, add HUD = nil; after that line.

It isn’t a memory leak; it is an over-release. Or, more likely, a dangling reference.

(and of course I do not release it in
my dealloc)

Why not? If you retain it, you better release it!