MBProgressHUD causes application to crash
It seems that using MBProgressHUD is causing my application to crash. Without the HUD code, the following runs just fine, but with it, it crashes:
{
...
HUD = [[MBProgressHUD alloc] initWithView:self.view];
// Add HUD to screen
[self.view addSubview:HUD];
// Register for HUD callbacks so we can remove it from the window at the right time
HUD.delegate = self;
HUD.labelText = @"Connecting";
// Show the HUD while the provided method executes in a new thread
[HUD showWhileExecuting:@selector(runLocalNotificationHandler) onTarget:self withObject:nil animated:YES];
[[self navigationController] popViewControllerAnimated:YES];
}
- (void) runLocalNotificationHandler
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
[self createLocalNotificationWithBug:[self tempBug]];
[self performSelectorOnMainThread:@selector(finishedUpdatingNotifications) withObject:nil waitUntilDone:NO];
[pool release];
}
- (void)finishedUpdatingNotifications
{
[[self navigationController] popViewControllerAnimated:YES];
}
- (void)hudWasHidden {
// Remove HUD from screen when the HUD was hidden
[HUD removeFromSuperview];
[HUD release];
}
The following debug output is produced:
gdb) continue
2010-07-02 00:07:55.224 Bugger[16796:207] >>> Entering -[HomeViewController viewDidAppear:] <<<
2010-07-02 00:07:55.225 Bugger[16796:207] <<< Leaving -[HomeViewController viewDidAppear:] >>>
2010-07-02 00:07:55.224 Bugger[16796:7007] <<< Leaving -[BugDetailViewController runLocalNotificationHandler] >>>
2010-07-02 00:07:55.226 Bugger[16796:207] >>> Entering -[BugDetailViewController prepareToolbar] <<<
2010-07-02 00:07:55.227 Bugger[16796:207] <<< Leaving -[BugDetailViewController prepareToolbar] >>>
2010-07-02 00:07:55.229 Bugger[16796:207] >>> Entering -[BugDetailViewController dealloc] <<<
[Switching to process 16开发者_StackOverflow796]
2010-07-02 00:07:55.260 Bugger[16796:207] <<< Leaving -[BugDetailViewController dealloc] >>>
[Switching to process 16796]
Program received signal: “EXC_BAD_ACCESS”.
(gdb)
What's going on here?
EDIT: Backtrace:
Program received signal: “EXC_BAD_ACCESS”.
[Switching to process 23788]
(gdb) bt
#0 0x029b4a93 in objc_msgSend ()
#1 0x00000000 in ?? ()
(gdb)
i had a similar issue with this combination of MBProgress and navigationController, for some reason looks like you can not call navigation controller actions from a selector call, you must use navigation events only in the main thread, hope this helps.
So close....
type bt<return>
at that (gdb)
prompt and post the backtrace.
Beyond that, my best guess is that your delegate -- the self
in the above code -- is being released and deallocated without first being removed as delegate from the MBProgressHUD
instance. Delegates are typically a weak reference and, thus, that would definitely cause a crash as you describe.
Ewwww... your stack has been stomped! I hate it when that happens.
Back to the best guess; is your delegate being deallocated before being removed as the delegate from the MBProgressHUD
? ... have you run "Build and Analyze" on your code?
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